'Get unit vectors and scale factors from (unit)spherical base.
Parameters
base : instance of ``self.base_representation``
The points for which the unit vectors and scale factors should be
retrieved.
Returns
unit_vectors : dict of `CartesianRepresentation`
In the directions of the coordinates of base.
scale_factors : dict of `~astropy.units.Quantity`
Scale factors for each of the coordinates.  The scale factor for
longitude does not include the cos(lat) factor.
Raises
TypeError : if the base is not of the correct type'

@classmethod
def _get_base_vectors(cls, base):

    cls._check_base(base)
    return (base.unit_vectors(), base.scale_factors(omit_coslat=True))
