class Spec::Expectations::NegativeExpectationMatcherHandler

def handle_matcher(actual, matcher, &block)
  ::Spec::Matchers.last_should = "should not"
  return Spec::Matchers::NegativeOperatorMatcher.new(actual) if matcher.nil?
  
  unless matcher.respond_to?(:matches?)
    raise InvalidMatcherError, "Expected a matcher, got #{matcher.inspect}."
  end
  unless matcher.respond_to?(:negative_failure_message)
    Spec::Expectations.fail_with(
does not support should_not.
::Matchers for more information
tchers.
  end
  match = matcher.matches?(actual, &block)
  ::Spec::Matchers.last_matcher = matcher
  Spec::Expectations.fail_with(matcher.negative_failure_message) if match
  match
end