When is interface duplication okay?

  • having methods with the same signature is not always bad. the important thing is that each new method should contribute significant functionality. pass-through methods are bad because they contribute no new functionality.
  • An example of a useful method to call another method with the same signature is a dispatcher
  • it’s fine for several methods to have the same signature as long as each of them provides useful and distinct functionality.
  • decorator design pattern is one that encourages API duplication across layers. A decorator object takes an existing object and extends its functionality it provides an API similar or identical to an underlying object.