block_given? doesn't work in a delegating BasicObject

block_given.rb

class Foo < BasicObject
  def test_block_given?
    block_given?
  end
  
  private
  def method_missing(method, *args, &block)
    3.send(method, *args, &block)
  end
end

Foo.new.test_block_given? {} # => false