if (a < 0)
while (a < start)
  public boolean containsAngle(double a)  {    double start = getAngleStart();    double end = start + getAngleExtent();    start %= 360;    if (start < 0)      start += 360;    end %= 360;    if (end < 0)      end += 360;    a %= 360;    if (a < 0)      a += 360;    return a >= start && a <= end;	}