Let’s take the GetSongUseCase example itself, suppose instead of call we named the function as myFunction. So to use the function we will do something like this - Copy Copy GetSongUseCase object = GetSongUseCase(); result = object.myFunction(); But using the call method we can simplify this as - Copy Copy result = GetSongUseCase(); The call method will automatically get executed for us. this point is wrong u used the call with wrong way