def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def __init__(self, w, h, color = "empty"):
		self.board = zeros((h,w), dtype=uint8)
		self.w = w
		self.h = h
		self.set_brush(color)