direction = int range(0, 4)

            0 = Down
            1 = Left
            2 = Up
            3 = Right

def move(self, direction=0):
        """
            direction = int range(0, 4)

            0 = Down
            1 = Left
            2 = Up
            3 = Right
        """
        direction = int(direction)
        self.position = list(self.position)

        if direction == 0:
            self.position[1] += 1
        elif direction == 1:
            self.position[0] -= 1
        elif direction == 2:
            self.position[1] -= 1
        elif direction == 3:
            self.position[0] += 1