"""Provides a World class to allow a Ball to query the dimensions of the world."""

class World:
    def __init__(self, w, h):
        self._w = w
        self._h = h
        self._balls = set()

    def getWidth(self):
        return self._w

    def getHeight(self):
        return self._h
    
    def getBalls(self):
        return list(self._balls)

    def addBall(self, b):
        return self._balls.add(b)

    def removeBall(self, b):
        return self._balls.discard(b)