Many systems provide the ability to have alternatives to visual or other sensory attributes (such as color or sound) for the purpose of accessibility (for example a picture to be displayed on a web page may have a textual alternative that could be read by a text-to-speech peripheral for the usually impaired). define an interface accessibleguiattribute that contains a single method, getalternativetext, that returns a string representing the textual alternative of an object. getalternatrive accepts no parameters.210)