'''World.py: the interface that ServerWorld and LocalWorld each implement'''

class World():
    def addListener(self, listener):
        '''addListener: associate a new listener with the world. When the world
            updates, it updates all of its listeners, all of whom implement
            the WorldListener interface.'''
        pass

    def removeListener(self, listener):
        """removeListener: remove the association created with addListener. This 
            WorldListener will no longer receive updates."""
        pass

    def setSpecies(self, x, y, species):
        '''accepts the things you would need to set a species.
        
        IMPORTANT PART: setSpecies returns a boolean indicating if the set was
        successful or not.
        
        It is fine for the Local implementation to always return True, but
        in the Net implementation the server needs to confirm that the change
        was allowed at the time '''
        pass
        
    '''please add additional methods as necessary'''