diff --git a/app/src/main/kotlin/info/appdev/chartexample/DynamicalAddingActivity.kt b/app/src/main/kotlin/info/appdev/chartexample/DynamicalAddingActivity.kt
index e19d46ab9f..8f1c7d9e7b 100644
--- a/app/src/main/kotlin/info/appdev/chartexample/DynamicalAddingActivity.kt
+++ b/app/src/main/kotlin/info/appdev/chartexample/DynamicalAddingActivity.kt
@@ -148,7 +148,7 @@ class DynamicalAddingActivity : DemoBase(), OnChartValueSelectedListener {
     }
 
     private fun createSet(): LineDataSet {
-        val set = LineDataSet(null, "DataSet 1")
+        val set = LineDataSet(label = "DataSet 1")
         set.lineWidth = 2.5f
         set.circleRadius = 4.5f
         set.color = Color.rgb(240, 99, 99)
diff --git a/app/src/main/kotlin/info/appdev/chartexample/RealtimeLineChartActivity.kt b/app/src/main/kotlin/info/appdev/chartexample/RealtimeLineChartActivity.kt
index 0a96a52329..ec29eede4a 100644
--- a/app/src/main/kotlin/info/appdev/chartexample/RealtimeLineChartActivity.kt
+++ b/app/src/main/kotlin/info/appdev/chartexample/RealtimeLineChartActivity.kt
@@ -113,7 +113,7 @@ class RealtimeLineChartActivity : DemoBase(), OnChartValueSelectedListener {
     }
 
     private fun createSet(): LineDataSet {
-        val set = LineDataSet(null, "Dynamic Data")
+        val set = LineDataSet(label = "Dynamic Data")
         set.axisDependency = AxisDependency.LEFT
         set.color = ColorTemplate.holoBlue
         set.setCircleColor(Color.WHITE)
diff --git a/app/src/main/kotlin/info/appdev/chartexample/compose/HorizontalBarComposeActivity.kt b/app/src/main/kotlin/info/appdev/chartexample/compose/HorizontalBarComposeActivity.kt
index de964dc15a..4a555df6ec 100644
--- a/app/src/main/kotlin/info/appdev/chartexample/compose/HorizontalBarComposeActivity.kt
+++ b/app/src/main/kotlin/info/appdev/chartexample/compose/HorizontalBarComposeActivity.kt
@@ -354,7 +354,7 @@ class HorizontalBarComposeActivity : DemoBaseCompose() {
         if (chartData != null && chartData.dataSetCount > 0) {
             set1 = chartData.getDataSetByIndex(0) as BarDataSet
             @Suppress("DEPRECATION")
-            set1.values = values
+            set1.entries = values
             chartData.notifyDataChanged()
             localChart.notifyDataSetChanged()
         } else {
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/BarLineScatterCandleBubbleDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/BarLineScatterCandleBubbleDataSet.kt
index 4b5a113912..fbc22d82ee 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/BarLineScatterCandleBubbleDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/BarLineScatterCandleBubbleDataSet.kt
@@ -7,7 +7,7 @@ import info.appdev.charting.interfaces.datasets.IBarLineScatterCandleBubbleDataS
 /**
  * Baseclass of all DataSets for Bar-, Line-, Scatter- and CandleStickChart.
  */
-abstract class BarLineScatterCandleBubbleDataSet<T : Entry>(yVals: MutableList<T>?, label: String) :
+abstract class BarLineScatterCandleBubbleDataSet<T : Entry>(yVals: MutableList<T>, label: String) :
     DataSet<T>(yVals, label), IBarLineScatterCandleBubbleDataSet<T> {
     /**
      * Sets the color that is used for drawing the highlight indicators.
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/BubbleDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/BubbleDataSet.kt
index cd872671a4..07f229a2c2 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/BubbleDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/BubbleDataSet.kt
@@ -3,7 +3,7 @@ package info.appdev.charting.data
 import info.appdev.charting.interfaces.datasets.IBubbleDataSet
 import info.appdev.charting.utils.convertDpToPixel
 
-open class BubbleDataSet(yVals: MutableList<BubbleEntry>?, label: String) : BarLineScatterCandleBubbleDataSet<BubbleEntry>(yVals, label), IBubbleDataSet {
+open class BubbleDataSet(yVals: MutableList<BubbleEntry>, label: String) : BarLineScatterCandleBubbleDataSet<BubbleEntry>(yVals, label), IBubbleDataSet {
     protected var mMaxSize: Float = 0f
     protected var mNormalizeSize: Boolean = true
 
@@ -21,8 +21,8 @@ open class BubbleDataSet(yVals: MutableList<BubbleEntry>?, label: String) : BarL
 
     override fun copy(): DataSet<BubbleEntry> {
         val entries: MutableList<BubbleEntry> = ArrayList()
-        for (i in mEntries!!.indices) {
-            entries.add(mEntries!![i].copy())
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
         val copied = BubbleDataSet(entries, label)
         copy(copied)
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/CandleDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/CandleDataSet.kt
index 47d4b821e5..13b2f1cc32 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/CandleDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/CandleDataSet.kt
@@ -9,7 +9,7 @@ import info.appdev.charting.utils.convertDpToPixel
 /**
  * DataSet for the CandleStickChart.
  */
-open class CandleDataSet(yVals: MutableList<CandleEntry>?, label: String = "") : LineScatterCandleRadarDataSet<CandleEntry>(yVals, label), ICandleDataSet {
+open class CandleDataSet(yVals: MutableList<CandleEntry>, label: String = "") : LineScatterCandleRadarDataSet<CandleEntry>(yVals, label), ICandleDataSet {
     /**
      * the width of the shadow of the candle
      */
@@ -72,10 +72,8 @@ open class CandleDataSet(yVals: MutableList<CandleEntry>?, label: String = "") :
 
     override fun copy(): DataSet<CandleEntry> {
         val entries: MutableList<CandleEntry> = mutableListOf()
-        mEntries?.let {
-            for (i in it.indices) {
-                entries.add(it[i].copy())
-            }
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
 
         val copied = CandleDataSet(entries, label)
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/DataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/DataSet.kt
index 8da5ca29c7..823d7ca46e 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/DataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/DataSet.kt
@@ -11,7 +11,7 @@ import kotlin.math.abs
  * LineChart, or the values of a specific group of bars in the BarChart).
  */
 abstract class DataSet<T : Entry>(
-    protected var mEntries: MutableList<T>?,
+    protected var mEntries: MutableList<T>,
     label: String = ""
 ) : BaseDataSet<T>(label), Serializable {
     /**
@@ -38,17 +38,12 @@ abstract class DataSet<T : Entry>(
     override var xMin: Float = Float.MAX_VALUE
         protected set
 
-
     /**
      * Creates a new DataSet object with the given values (entries) it represents. Also, a
      * label that describes the DataSet can be specified. The label can also be
      * used to retrieve the DataSet from a ChartData object.
      */
     init {
-        if (mEntries == null) {
-            mEntries = ArrayList<T>()
-        }
-
         calcMinMax()
     }
 
@@ -58,7 +53,7 @@ abstract class DataSet<T : Entry>(
         this.xMax = -Float.MAX_VALUE
         this.xMin = Float.MAX_VALUE
 
-        if (mEntries == null || mEntries!!.isEmpty()) {
+        if (mEntries.isEmpty()) {
             return
         }
 
@@ -71,7 +66,7 @@ abstract class DataSet<T : Entry>(
         this.yMax = -Float.MAX_VALUE
         this.yMin = Float.MAX_VALUE
 
-        if (mEntries == null || mEntries!!.isEmpty()) {
+        if (mEntries.isEmpty()) {
             return
         }
 
@@ -85,7 +80,7 @@ abstract class DataSet<T : Entry>(
         for (i in indexFrom..indexTo) {
             // only recalculate y
 
-            calcMinMaxY(mEntries!![i])
+            calcMinMaxY(mEntries[i])
         }
     }
 
@@ -118,32 +113,13 @@ abstract class DataSet<T : Entry>(
     }
 
     override val entryCount: Int
-        get() = mEntries!!.size
-
-    @get:Deprecated("")
-    @set:Deprecated("")
-    var values: MutableList<T>?
-        /**
-         * This method is deprecated.
-         * Use getEntries() instead.
-         */
-        get() = mEntries
-        /**
-         * This method is deprecated.
-         * Use setEntries(...) instead.
-         */
-        set(values) {
-            this.entries = values
-        }
+        get() = mEntries.size
 
-    var entries: MutableList<T>?
-        /**
-         * Returns the array of entries that this DataSet represents.
-         */
+    /**
+     * Returns the array of entries that this DataSet represents.
+     */
+    var entries: MutableList<T>
         get() = mEntries
-        /**
-         * Sets the array of entries that this DataSet represents, and calls notifyDataSetChanged()
-         */
         set(entries) {
             mEntries = entries
             notifyDataSetChanged()
@@ -161,8 +137,8 @@ abstract class DataSet<T : Entry>(
     override fun toString(): String {
         val buffer = StringBuilder()
         buffer.append(toSimpleString())
-        for (i in mEntries!!.indices) {
-            buffer.append(mEntries!![i].toString()).append(" ")
+        for (i in mEntries.indices) {
+            buffer.append(mEntries[i].toString()).append(" ")
         }
         return buffer.toString()
     }
@@ -170,33 +146,26 @@ abstract class DataSet<T : Entry>(
     /**
      * Returns a simple string representation of the DataSet with the type and the number of Entries.
      */
-    fun toSimpleString() = "DataSet, label: $label, entries: ${mEntries!!.size}"
+    fun toSimpleString() = "DataSet, label: $label, entries: ${mEntries.size}"
 
     override fun addEntryOrdered(entry: T) {
-        if (mEntries == null) {
-            mEntries = ArrayList()
-        }
-
         calcMinMax(entry)
 
-        if (!mEntries!!.isEmpty() && mEntries!![mEntries!!.size - 1].x > entry.x) {
+        if (!mEntries.isEmpty() && mEntries[mEntries.size - 1].x > entry.x) {
             val closestIndex = getEntryIndex(entry.x, entry.y, Rounding.UP)
-            mEntries!!.add(closestIndex, entry)
+            mEntries.add(closestIndex, entry)
         } else {
-            mEntries!!.add(entry)
+            mEntries.add(entry)
         }
     }
 
     override fun clear() {
-        mEntries!!.clear()
+        mEntries.clear()
         notifyDataSetChanged()
     }
 
     override fun addEntry(entry: T): Boolean {
-        var values = this.entries
-        if (values == null) {
-            values = ArrayList()
-        }
+        val values = this.entries
 
         calcMinMax(entry)
 
@@ -205,11 +174,9 @@ abstract class DataSet<T : Entry>(
     }
 
     override fun removeEntry(entry: T): Boolean {
-        if (mEntries == null)
-            return false
 
         // remove the entry
-        val removed = mEntries!!.remove(entry)
+        val removed = mEntries.remove(entry)
 
         if (removed) {
             calcMinMax()
@@ -220,14 +187,14 @@ abstract class DataSet<T : Entry>(
 
     override fun getEntryIndex(entry: T): Int {
 //        return getEntryIndex(entry)
-        return mEntries!!.indexOf(entry)
+        return mEntries.indexOf(entry)
     }
 
 
     override fun getEntryForXValue(xValue: Float, closestToY: Float, rounding: Rounding?): T? {
         val index = getEntryIndex(xValue, closestToY, rounding)
         if (index > -1) {
-            return mEntries!![index]
+            return mEntries[index]
         }
         return null
     }
@@ -240,28 +207,28 @@ abstract class DataSet<T : Entry>(
         if (index < 0) {
             Timber.e("index $index is < 0 for getEntryForIndex")
             return null
-        } else if (index >= mEntries!!.size) {
-            Timber.e("index " + index + "/" + mEntries!!.size + " is out of range for getEntryForIndex")
+        } else if (index >= mEntries.size) {
+            Timber.e("index $index / ${mEntries.size} is out of range for getEntryForIndex")
             return null
         }
-        return mEntries!![index]
+        return mEntries[index]
     }
 
     override fun getEntryIndex(xValue: Float, closestToY: Float, rounding: Rounding?): Int {
-        if (mEntries == null || mEntries!!.isEmpty()) {
+        if (mEntries.isEmpty()) {
             return -1
         }
 
         var low = 0
-        var high = mEntries!!.size - 1
+        var high = mEntries.size - 1
         var closest = high
 
         while (low < high) {
             val m = low + (high - low) / 2
 
-            val currentEntry: Entry = mEntries!![m]
+            val currentEntry: Entry = mEntries[m]
 
-            val nextEntry: Entry = mEntries!![m + 1]
+            val nextEntry: Entry = mEntries[m + 1]
 
             val d1 = currentEntry.x - xValue
             val d2 = nextEntry.x - xValue
@@ -291,11 +258,11 @@ abstract class DataSet<T : Entry>(
             closest = high
         }
 
-        val closestEntry: Entry = mEntries!![closest]
+        val closestEntry: Entry = mEntries[closest]
         val closestXValue = closestEntry.x
         if (rounding == Rounding.UP) {
             // If rounding up, and found x-value is lower than specified x, and we can go upper...
-            if (closestXValue < xValue && closest < mEntries!!.size - 1) {
+            if (closestXValue < xValue && closest < mEntries.size - 1) {
                 ++closest
             }
         } else if (rounding == Rounding.DOWN) {
@@ -307,7 +274,7 @@ abstract class DataSet<T : Entry>(
 
         // Search by closest to y-value
         if (!closestToY.isNaN()) {
-            while (closest > 0 && mEntries!![closest - 1].x == closestXValue) {
+            while (closest > 0 && mEntries[closest - 1].x == closestXValue) {
                 closest -= 1
             }
 
@@ -316,11 +283,11 @@ abstract class DataSet<T : Entry>(
 
             while (true) {
                 closest += 1
-                if (closest >= mEntries!!.size) {
+                if (closest >= mEntries.size) {
                     break
                 }
 
-                val value: T = mEntries!![closest]
+                val value: T = mEntries[closest]
 
                 if (value.x != closestXValue) {
                     break
@@ -341,23 +308,23 @@ abstract class DataSet<T : Entry>(
         val entries: MutableList<T> = mutableListOf()
 
         var low = 0
-        var high = mEntries!!.size - 1
+        var high = mEntries.size - 1
 
         while (low <= high) {
             var m = (high + low) / 2
-            var entry = mEntries!![m]
+            var entry = mEntries[m]
 
             // if we have a match
             if (xValue == entry.x) {
-                while (m > 0 && mEntries!![m - 1].x == xValue) {
+                while (m > 0 && mEntries[m - 1].x == xValue) {
                     m--
                 }
 
-                high = mEntries!!.size
+                high = mEntries.size
 
                 // loop over all "equal" entries
                 while (m < high) {
-                    entry = mEntries!![m]
+                    entry = mEntries[m]
                     if (entry.x == xValue) {
                         entries.add(entry)
                     } else {
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/LineDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/LineDataSet.kt
index 9627f21845..9f00dc2555 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/LineDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/LineDataSet.kt
@@ -12,15 +12,12 @@ import info.appdev.charting.utils.ColorTemplate
 import info.appdev.charting.utils.convertDpToPixel
 import timber.log.Timber
 
-open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRadarDataSet<Entry>(yVals, label), ILineDataSet {
+open class LineDataSet(yVals: MutableList<Entry> = mutableListOf(), label: String = "") : LineRadarDataSet<Entry>(yVals, label), ILineDataSet {
     /**
      * Drawing mode for this line dataset
      */
     private var mLineDataSetMode: Mode = Mode.LINEAR
 
-    /**
-     * returns all colors specified for the circles
-     */
     /**
      * Sets the colors that should be used for the circles of this DataSet.
      * Colors are reused as soon as the number of Entries the DataSet represents
@@ -28,9 +25,6 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
      * are already prepared (by calling getResources().getColor(...)) before
      * adding them to the DataSet.
      */
-    /**
-     * List representing all colors that are used for the circles
-     */
     @ColorInt
     var circleColors: MutableList<Int> = mutableListOf()
 
@@ -72,7 +66,6 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
 
     private var mDrawCircleHole = true
 
-
     init {
         // default colors
         // mColors.add(Color.rgb(192, 255, 140));
@@ -82,10 +75,8 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
 
     override fun copy(): DataSet<Entry> {
         val entries: MutableList<Entry> = mutableListOf()
-        mEntries?.let {
-            for (i in it.indices) {
-                entries.add(it[i].copy())
-            }
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
         val copied = LineDataSet(entries, label)
         copy(copied)
@@ -128,13 +119,14 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
         set(value) {
             mLineDataSetMode = value
         }
+
+    /**
+     * Sets the intensity for cubic lines (if enabled). Max = 1f = very cubic,
+     * Min = 0.05f = low cubic effect, Default: 0.2f
+     */
     override var cubicIntensity: Float
         get() = mCubicIntensity
         set(value) {
-            /**
-             * Sets the intensity for cubic lines (if enabled). Max = 1f = very cubic,
-             * Min = 0.05f = low cubic effect, Default: 0.2f
-             */
             var intensity = value
             if (intensity > 1f) {
                 intensity = 1f
@@ -152,13 +144,13 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
     override val isDrawSteppedEnabled: Boolean
         get() = mLineDataSetMode == Mode.STEPPED
 
+    /**
+     * Sets the radius of the drawn circles.
+     * Default radius = 4f, Min = 1f
+     */
     override var circleRadius: Float
         get() = mCircleRadius
         set(value) {
-            /**
-             * Sets the radius of the drawn circles.
-             * Default radius = 4f, Min = 1f
-             */
             if (value >= 1f) {
                 mCircleRadius = value.convertDpToPixel()
             } else {
@@ -166,13 +158,13 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
             }
         }
 
+    /**
+     * Sets the hole radius of the drawn circles.
+     * Default radius = 2f, Min = 0.5f
+     */
     override var circleHoleRadius: Float
         get() = mCircleHoleRadius
         set(value) {
-            /**
-             * Sets the hole radius of the drawn circles.
-             * Default radius = 2f, Min = 0.5f
-             */
             if (value >= 0.5f) {
                 mCircleHoleRadius = value.convertDpToPixel()
             } else {
@@ -224,11 +216,7 @@ open class LineDataSet(yVals: MutableList<Entry>?, label: String = "") : LineRad
     override var fillFormatter: IFillFormatter?
         get() = mFillFormatter
         set(value) {
-            if (value == null) {
-                mFillFormatter = DefaultFillFormatter()
-            } else {
-                mFillFormatter = value
-            }
+            mFillFormatter = value ?: DefaultFillFormatter()
         }
 
     /**
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/LineRadarDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/LineRadarDataSet.kt
index 5b39cff2d8..fabb6c1282 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/LineRadarDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/LineRadarDataSet.kt
@@ -9,7 +9,7 @@ import info.appdev.charting.utils.convertDpToPixel
 /**
  * Base dataset for line and radar DataSets.
  */
-abstract class LineRadarDataSet<T : Entry>(yVals: MutableList<T>?, label: String) : LineScatterCandleRadarDataSet<T>(yVals, label), ILineRadarDataSet<T> {
+abstract class LineRadarDataSet<T : Entry>(yVals: MutableList<T>, label: String) : LineScatterCandleRadarDataSet<T>(yVals, label), ILineRadarDataSet<T> {
     // TODO: Move to using `Fill` class
     /**
      * the color that is used for filling the line surface
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/LineScatterCandleRadarDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/LineScatterCandleRadarDataSet.kt
index 0fa003ffd7..f31b5587fb 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/LineScatterCandleRadarDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/LineScatterCandleRadarDataSet.kt
@@ -4,7 +4,7 @@ import android.graphics.DashPathEffect
 import info.appdev.charting.interfaces.datasets.ILineScatterCandleRadarDataSet
 import info.appdev.charting.utils.convertDpToPixel
 
-abstract class LineScatterCandleRadarDataSet<T : Entry>(yVals: MutableList<T>?, label: String) : BarLineScatterCandleBubbleDataSet<T>(yVals, label),
+abstract class LineScatterCandleRadarDataSet<T : Entry>(yVals: MutableList<T>, label: String) : BarLineScatterCandleBubbleDataSet<T>(yVals, label),
     ILineScatterCandleRadarDataSet<T> {
     override var isVerticalHighlightIndicatorEnabled: Boolean = true
         protected set
@@ -76,11 +76,11 @@ abstract class LineScatterCandleRadarDataSet<T : Entry>(yVals: MutableList<T>?,
         this.dashPathEffectHighlight = null
     }
 
+    /**
+     * Returns true if the dashed-line effect is enabled for highlight lines, false if not.
+     * Default: disabled
+     */
     val isDashedHighlightLineEnabled: Boolean
-        /**
-         * Returns true if the dashed-line effect is enabled for highlight lines, false if not.
-         * Default: disabled
-         */
         get() = this.dashPathEffectHighlight != null
 
     protected fun copy(lineScatterCandleRadarDataSet: LineScatterCandleRadarDataSet<*>) {
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/PieDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/PieDataSet.kt
index 46cb68f28e..d3f263be7a 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/PieDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/PieDataSet.kt
@@ -4,7 +4,7 @@ import androidx.annotation.ColorInt
 import info.appdev.charting.interfaces.datasets.IPieDataSet
 import info.appdev.charting.utils.convertDpToPixel
 
-open class PieDataSet(yVals: MutableList<PieEntry>?, label: String) : DataSet<PieEntry>(yVals, label), IPieDataSet {
+open class PieDataSet(yVals: MutableList<PieEntry>, label: String) : DataSet<PieEntry>(yVals, label), IPieDataSet {
     /**
      * the space in pixels between the chart-slices, default 0f
      */
@@ -25,15 +25,14 @@ open class PieDataSet(yVals: MutableList<PieEntry>?, label: String) : DataSet<Pi
     private var mValueLinePart1Length = 0.3f
     private var mValueLinePart2Length = 0.4f
     private var mIsValueLineVariableLength = true
+
     @ColorInt
     private var mHighlightColor: Int? = null
 
     override fun copy(): DataSet<PieEntry> {
         val entries: MutableList<PieEntry> = mutableListOf()
-        mEntries?.let {
-            for (i in it.indices) {
-                entries.add(it[i].copy())
-            }
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
         val copied = PieDataSet(entries, label)
         return copied
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/RadarDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/RadarDataSet.kt
index 0b0893046d..ceca8885bd 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/RadarDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/RadarDataSet.kt
@@ -5,7 +5,7 @@ import androidx.annotation.ColorInt
 import info.appdev.charting.interfaces.datasets.IRadarDataSet
 import info.appdev.charting.utils.ColorTemplate
 
-open class RadarDataSet(yVals: MutableList<RadarEntry>?, label: String = "") : LineRadarDataSet<RadarEntry>(yVals, label), IRadarDataSet {
+open class RadarDataSet(yVals: MutableList<RadarEntry>, label: String = "") : LineRadarDataSet<RadarEntry>(yVals, label), IRadarDataSet {
     /** flag indicating whether highlight circle should be drawn or not */
     protected var mDrawHighlightCircleEnabled: Boolean = false
 
@@ -60,10 +60,8 @@ open class RadarDataSet(yVals: MutableList<RadarEntry>?, label: String = "") : L
 
     override fun copy(): DataSet<RadarEntry> {
         val entries: MutableList<RadarEntry> = mutableListOf()
-        mEntries?.let {
-            for (i in it.indices) {
-                entries.add(it[i].copy())
-            }
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
         val copied = RadarDataSet(entries, label)
         copy(copied)
diff --git a/chartLib/src/main/kotlin/info/appdev/charting/data/ScatterDataSet.kt b/chartLib/src/main/kotlin/info/appdev/charting/data/ScatterDataSet.kt
index 8ab7fa3b03..0b1b5dcbb9 100644
--- a/chartLib/src/main/kotlin/info/appdev/charting/data/ScatterDataSet.kt
+++ b/chartLib/src/main/kotlin/info/appdev/charting/data/ScatterDataSet.kt
@@ -13,7 +13,7 @@ import info.appdev.charting.renderer.scatter.TriangleShapeRenderer
 import info.appdev.charting.renderer.scatter.XShapeRenderer
 import info.appdev.charting.utils.ColorTemplate
 
-open class ScatterDataSet(yVals: MutableList<Entry>?, label: String = "") : LineScatterCandleRadarDataSet<Entry>(yVals, label), IScatterDataSet {
+open class ScatterDataSet(yVals: MutableList<Entry>, label: String = "") : LineScatterCandleRadarDataSet<Entry>(yVals, label), IScatterDataSet {
     /**
      * the size the scatterShape will have, in density pixels
      */
@@ -40,10 +40,8 @@ open class ScatterDataSet(yVals: MutableList<Entry>?, label: String = "") : Line
 
     override fun copy(): DataSet<Entry> {
         val entries: MutableList<Entry> = mutableListOf()
-        mEntries?.let {
-            for (i in it.indices) {
-                entries.add(it[i].copy())
-            }
+        for (i in mEntries.indices) {
+            entries.add(mEntries[i].copy())
         }
         val copied = ScatterDataSet(entries, label)
         copy(copied)