code: function(actual) {
        function assert(matcher, args, negate) {
          var expected = toArray(args, 1)
          matcher.negate = negate  
          assertion = new JSpec.Assertion(matcher, actual, expected, negate)
          hook('beforeAssertion', assertion)
          if (matcher.defer) assertion.run()
          else JSpec.currentSpec.assertions.push(assertion.run().report()), hook('afterAssertion', assertion)
          return assertion.result
        }
        
        function to(matcher) {
          return assert(matcher, arguments, false)
        }
        
        function not_to(matcher) {
          return assert(matcher, arguments, true)
        }
        
        return {
          to : to,
          should : to,
          not_to: not_to,
          should_not : not_to
        }
      }
docs: Perform an assertion.
  
  expect(true).to('be', true)
  expect('foo').not_to('include', 'bar')
  expect([1, [2]]).to('include', 1, [2])
  
  @param  {mixed} actual
  @return {hash}
  @api public