@staticmethod
def shortest_angle(a0, a1):
    """
        Calculate the shortest angle distance between a0 and a1

        Parameters
        ----------
        a0 : int | float
            angle 0 in degrees
        a1 : int | float
            angle 1 in degrees

        Returns
        -------
        da : int | float
            shortest angle distance between a0 and a1
        """
    da = (a1 - a0) % 360
    return 2 * da % 360 - da
