# File lib/rspec/mocks/message_expectation.rb, line 39
      def build_child(expected_from, expected_received_count, opts={}, &implementation)
        child = clone
        child.expected_from = expected_from
        child.implementation = implementation if implementation
        child.expected_received_count = expected_received_count
        child.clear_actual_received_count!
        new_gen = error_generator.clone
        new_gen.opts = opts
        child.error_generator = new_gen
        child.clone_args_to_yield(*@args_to_yield)
        child.argument_list_matcher = ArgumentListMatcher.new(ArgumentMatchers::AnyArgsMatcher.new)
        child
      end