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

replace 

        # Set.replace

(from ruby core)
---
    replace(enum)

---

Replaces the contents of the set with the contents of the given
enumerable object and returns self.
    set = Set[1, 'c', :s]             #=> #<Set: {1, "c", :s}>
    set.replace([1, 2])               #=> #<Set: {1, 2}>
    set                               #=> #<Set: {1, 2}>

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.