This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.

include? 

        # Array.include?

(from ruby core)
---
    array.include?(obj) -> true or false

---

Returns `true` if for some index `i` in `self`, `obj == self[i]`;
otherwise `false`:
    [0, 1, 2].include?(2) # => true
    [0, 1, 2].include?(3) # => false

This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.