How to use the geographiclib.geomath.Math.AngDiff function in geographiclib

def _transit(lon1, lon2):
    """Count crossings of prime meridian for AddPoint."""
    # Return 1 or -1 if crossing prime meridian in east or west direction.
    # Otherwise return zero.
    # Compute lon12 the same way as Geodesic::Inverse.
    lon1 = Math.AngNormalize(lon1)
    lon2 = Math.AngNormalize(lon2)
    lon12, _ = Math.AngDiff(lon1, lon2)
    cross = (1 if lon1 <= 0 and lon2 > 0 and lon12 > 0
             else (-1 if lon2 <= 0 and lon1 > 0 and lon12 < 0 else 0))
    return cross
  _transit = staticmethod(_transit)

def _transit(lon1, lon2):
    """Count crossings of prime meridian for AddPoint."""
    # Return 1 or -1 if crossing prime meridian in east or west direction.
    # Otherwise return zero.
    # Compute lon12 the same way as Geodesic::Inverse.
    lon1 = Math.AngNormalize(lon1)
    lon2 = Math.AngNormalize(lon2)
    lon12, _ = Math.AngDiff(lon1, lon2)
    cross = (1 if lon1 <= 0 and lon2 > 0 and lon12 > 0
             else (-1 if lon2 <= 0 and lon1 > 0 and lon12 < 0 else 0))
    return cross
  _transit = staticmethod(_transit)

def GenInverse(self, lat1, lon1, lat2, lon2, outmask):
    """Private: General version of the inverse problem"""
    a12 = s12 = azi1 = azi2 = m12 = M12 = M21 = S12 = Math.nan # return vals

    outmask &= Geodesic.OUT_ALL
    # Compute longitude difference (AngDiff does this carefully).  Result is
    # in [-180, 180] but -180 is only for west-going geodesics.  180 is for
    # east-going and meridional geodesics.
    lon12 = Math.AngDiff(Math.AngNormalize(lon1), Math.AngNormalize(lon2))
    # If very close to being on the same half-meridian, then make it so.
    lon12 = Geodesic.AngRound(lon12)
    # Make longitude difference positive.
    lonsign = 1 if lon12 >= 0 else -1
    lon12 *= lonsign
    # If really close to the equator, treat as on equator.
    lat1 = Geodesic.AngRound(lat1)
    lat2 = Geodesic.AngRound(lat2)
    # Swap points so that point with higher (abs) latitude is point 1
    swapp = 1 if abs(lat1) >= abs(lat2) else -1
    if swapp < 0:
      lonsign *= -1
      lat2, lat1 = lat1, lat2
    # Make lat1 <= 0
    latsign = 1 if lat1 < 0 else -1
    lat1 *= latsign

def _GenInverse(self, lat1, lon1, lat2, lon2, outmask):
    """Private: General version of the inverse problem"""
    a12 = s12 = m12 = M12 = M21 = S12 = Math.nan # return vals

    outmask &= Geodesic.OUT_MASK
    # Compute longitude difference (AngDiff does this carefully).  Result is
    # in [-180, 180] but -180 is only for west-going geodesics.  180 is for
    # east-going and meridional geodesics.
    lon12, lon12s = Math.AngDiff(lon1, lon2)
    # Make longitude difference positive.
    lonsign = 1 if lon12 >= 0 else -1
    # If very close to being on the same half-meridian, then make it so.
    lon12 = lonsign * Math.AngRound(lon12)
    lon12s = Math.AngRound((180 - lon12) - lonsign * lon12s)
    lam12 = math.radians(lon12)
    if lon12 > 90:
      slam12, clam12 = Math.sincosd(lon12s); clam12 = -clam12
    else:
      slam12, clam12 = Math.sincosd(lon12)

    # If really close to the equator, treat as on equator.
    lat1 = Math.AngRound(Math.LatFix(lat1))
    lat2 = Math.AngRound(Math.LatFix(lat2))
    # Swap points so that point with higher (abs) latitude is point 1
    # If one latitude is a nan, then it becomes lat1.

:param lon2: longitude of the second point in degrees
    :param outmask: the :ref:`output mask `
    :return: a :ref:`dict`

    Compute geodesic between (*lat1*, *lon1*) and (*lat2*, *lon2*).
    The default value of *outmask* is STANDARD, i.e., the *lat1*,
    *lon1*, *azi1*, *lat2*, *lon2*, *azi2*, *s12*, *a12* entries are
    returned.

    """

    a12, s12, salp1,calp1, salp2,calp2, m12, M12, M21, S12 = self._GenInverse(
      lat1, lon1, lat2, lon2, outmask)
    outmask &= Geodesic.OUT_MASK
    if outmask & Geodesic.LONG_UNROLL:
      lon12, e = Math.AngDiff(lon1, lon2)
      lon2 = (lon1 + lon12) + e
    else:
      lon2 = Math.AngNormalize(lon2)
    result = {'lat1': Math.LatFix(lat1),
              'lon1': lon1 if outmask & Geodesic.LONG_UNROLL else
              Math.AngNormalize(lon1),
              'lat2': Math.LatFix(lat2),
              'lon2': lon2}
    result['a12'] = a12
    if outmask & Geodesic.DISTANCE: result['s12'] = s12
    if outmask & Geodesic.AZIMUTH:
      result['azi1'] = Math.atan2d(salp1, calp1)
      result['azi2'] = Math.atan2d(salp2, calp2)
    if outmask & Geodesic.REDUCEDLENGTH: result['m12'] = m12
    if outmask & Geodesic.GEODESICSCALE:
      result['M12'] = M12; result['M21'] = M21

def _GenInverse(self, lat1, lon1, lat2, lon2, outmask):
    """Private: General version of the inverse problem"""
    a12 = s12 = m12 = M12 = M21 = S12 = Math.nan # return vals

    outmask &= Geodesic.OUT_MASK
    # Compute longitude difference (AngDiff does this carefully).  Result is
    # in [-180, 180] but -180 is only for west-going geodesics.  180 is for
    # east-going and meridional geodesics.
    lon12, lon12s = Math.AngDiff(lon1, lon2)
    # Make longitude difference positive.
    lonsign = 1 if lon12 >= 0 else -1
    # If very close to being on the same half-meridian, then make it so.
    lon12 = lonsign * Math.AngRound(lon12)
    lon12s = Math.AngRound((180 - lon12) - lonsign * lon12s)
    lam12 = math.radians(lon12)
    if lon12 > 90:
      slam12, clam12 = Math.sincosd(lon12s); clam12 = -clam12
    else:
      slam12, clam12 = Math.sincosd(lon12)

    # If really close to the equator, treat as on equator.
    lat1 = Math.AngRound(Math.LatFix(lat1))
    lat2 = Math.AngRound(Math.LatFix(lat2))
    # Swap points so that point with higher (abs) latitude is point 1
    # If one latitude is a nan, then it becomes lat1.