Id conflict for AttributeKey<T> with different types

[yyjdelete]

Unlike java, which does generic type erase; AttributeKey<Class1> and AttributeKey<Class2> are 2 different types in dotnet, that mean they will use 2 separate AttributeConstantPool, and can both the same Id.

That will make DefaultAttributeMap inefficient(still work, just inefficient)
, because it always use bucket-1, and never use 0,2,3 when you use more than 1 AttributeKey<T> and always with different types.

Maybe AttributeKey<T> needed to be separated to 2 types(like System.Tuple and System.Tuple<T1,...>), use an new utils class static class AttributeKey to hold all static methods and fields(or just fields for binary compatibility), and use the old sealed class AttributeKey<T> : AbstractConstant<AttributeKey<T>> for the data class itself.

***NOTE: *** It's always not safe for binary compatibility, since AttributeKey<T>.Pool is an public static field, and may be used by libs.
Can be marked as Obsolete and set AttributeKey<T>.Pool = AttributeKey.Pool

DotNetty/src/DotNetty.Common/Utilities/AttributeKey.cs

Lines 15 to 17 in 72deeb9

	public sealed class AttributeKey<T> : AbstractConstant<AttributeKey<T>>
	{
	public static readonly ConstantPool Pool = new AttributeConstantPool();

DotNetty/src/DotNetty.Common/Utilities/DefaultAttributeMap.cs

Line 35 in 72deeb9

int i = Index(key);