extending class -using super(in method definitions method extension for the case of single-inheritance is illustrated in the employee-manager class hierarchy shown on slide note how the derived-class promote(calls the base-class promote()and how the derived-class myprint(calls the base-class myprint(as you will see laterextending methods in multiple inheritance hierarchies requires calling super(to illustratesuppose we wish for method foo(in derived class to call on foo(in ' superclasses to do part of the workclass zabcd)def fooself )do something superzselffoo(in the next couple of slideswe will first consider the case of single inheritancethat iswhen each child class has single parent class purdue university