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compact 

        # Hash.compact

(from ruby core)
---
    hash.compact -> new_hash

---

Returns a copy of `self` with all `nil`-valued entries removed:
    h = {foo: 0, bar: nil, baz: 2, bat: nil}
    h1 = h.compact
    h1 # => {:foo=>0, :baz=>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.