def _last_index(self, s):
        self.set_index(max(0, self._find_one_after_last_labeled_index() - 1))
def line(self, x, y, length, horizontal):
		if horizontal:
			self.board[y,x:x+length] = self.color
		else:
			self.board[y:y+length,x] = self.color