class RSpec::Mocks::MessageExpectation

def and_yield(*args, &block)
  raise_already_invoked_error_if_necessary(__method__)
  yield @eval_context = Object.new if block
  # Initialize args to yield now that it's being used, see also: comment
  # in constructor.
  @args_to_yield ||= []
  @args_to_yield << args
  self.initial_implementation_action = AndYieldImplementation.new(@args_to_yield, @eval_context, @error_generator)
  self
end