"Black hole" Null Object - Responds to any chained message

gistfile1.rb

class NullObject < BasicObject
  def method_missing(*)
    self
  end

  def respond_to_missing?(name)
    true
  end
end

class Foo
  def bar(collaborator)
    collaborator.baz.boo.blah.bar.foo
  end
end

Foo.new.bar(NullObject.new)