Example code elaboration sought

[jsimmonds2]

The README.md example code enticingly suggests chained array methods are possible

users
  .map('friends')
  .select('age > 20 && age < 30')
  .map('name.first')
  .select(/^T/)

As a novice CoffeeScript and JS programmer, I'm having a struggle inventing a

users

object which allows the expected result to "come to life" !

Apologies if this question is spurious (i.e. silly or answered before)