/**
                             * ShouldError is subclass of Error that is thrown whenever
                             * a test is expected to throw an error but doesn't.
                             *
                             * @param {String} message The message to display when the error occurs.
                             * @namespace Test
                             * @extends AssertionError
                             * @module test
                             * @class ShouldError
                             * @constructor
                             */
                            YUITest.ShouldError = function (message){
                            
                                //call superclass
                                YUITest.AssertionError.call(this, message || "This test should have thrown an error but didn't.");
                            
                                /**
                                 * The name of the error that occurred.
                                 * @type String
                                 * @property name
                                 */
                                this.name = "ShouldError";
                            
                            };
                            
                            //inherit from YUITest.AssertionError
                            YUITest.ShouldError.prototype = new YUITest.AssertionError();
                            
                            //restore constructor
                            YUITest.ShouldError.prototype.constructor = YUITest.ShouldError;