class RSpec::Mocks::VerifyingMessageExpectation

def validate_arguments!(actual_args)
  return if method_reference.nil?
  method_reference.with_signature do |signature|
    verifier = Support::MethodSignatureVerifier.new(signature, actual_args)
    unless verifier.valid?
      # Fail fast is required, otherwise the message expecation will fail
      # as well ("expected method not called") and clobber this one.
      @failed_fast = true
      @error_generator.raise_invalid_arguments_error(verifier)
    end
  end
end