def helper_dimensionless_to_dimensionless(f, unit):
    if (unit is None):
        return ([None], dimensionless_unscaled)
    try:
        return ([get_converter(unit, dimensionless_unscaled)], dimensionless_unscaled)
    except UnitsError:
        raise UnitTypeError("Can only apply '{0}' function to dimensionless quantities".format(f.__name__))
def helper_dimensionless_to_dimensionless(f, unit):
    if (unit is None):
        return ([None], dimensionless_unscaled)
    try:
        return ([get_converter(unit, dimensionless_unscaled)], dimensionless_unscaled)
    except UnitsError:
        raise UnitTypeError("Can only apply '{0}' function to dimensionless quantities".format(f.__name__))