class RSpec::Mocks::ErrorGenerator

def raise_already_invoked_error(message, calling_customization)
  error_message = "The message expectation for #{intro}.#{message} has already been invoked " \
    "and cannot be modified further (e.g. using `#{calling_customization}`). All message expectation " \
    "customizations must be applied before it is used for the first time."
  notify MockExpectationAlreadyInvokedError.new(error_message)
end