def METHOD_NAME(self):
    # Test plotting vectors in a rotated latlon coord system.
    u_cube, v_cube = self._latlon_uv_cubes(sample_2d_latlons())
    patch_coord_system = Mercator()
    for cube in u_cube, v_cube:
        for coord in cube.coords():
            coord.coord_system = patch_coord_system
    re_msg = (
        r"Can only plot .* lat-lon projection, .* "
        r"This .* translates as Cartopy \+proj=merc .*"
    )
    with self.assertRaisesRegex(ValueError, re_msg):
        self.plot(
            "2d_rotated", u_cube, v_cube, coords=("longitude", "latitude")
        )