def handler():
            nonlocal called
            called += 1
            raise ValueError("yeah sync")
def mouse_rotate(xAngle, yAngle, zAngle):
    glRotatef(xAngle, 1.0, 0.0, 0.0);
    glRotatef(yAngle, 0.0, 1.0, 0.0);
    glRotatef(zAngle, 0.0, 0.0, 1.0);