def METHOD_NAME(self):
    exc = self.assert_mfd_error(
        YoungsCoppersmith1985MFD,
        min_mag=4.0, b_val=1.0, char_mag=4.3, char_rate=0.001,
        bin_width=0.1
    )
    error = ('Maximum magnitude of the G-R distribution (char_mag - 0.25) '
             'must be greater than the minimum magnitude by at least one '
             'magnitude bin.')
    self.assertEqual(str(exc), error)