You can't use `enum_for __method__` with inheritance 😢

ugh.rb

class A
  def m(&block)
    #return enum_for __method__ unless block_given?
    # The above calls the B implementation of #m so instead we have to create
    # our own Enumerator that's bound to this class' method so we can run the
    # with-block version of this method
    unless block_given? then
      enum = Enumerator.new do |yielder|
        method = A.instance_method(__method__).bind self

        block = proc do |object|
          yielder << object
        end

        method.call(&block)
      end

      return enum
    end

    yield 1
    yield 1
    yield 2
    yield 2
    yield 3
    yield 3
  end
end

class B < A
  def m(&block)
    return enum_for __method__ unless block_given?

    super(&nil).uniq.each do |number|
      yield number * number
    end
  end
end

p B.new.m.to_a