def METHOD_NAME(self):
    test_cube = self._make_test_cube(x_points=[1e6, 3e6, 5e6, 7e6],
                                     y_points=[4e6, 9e6])
    grid_definition_template_30(test_cube, self.mock_grib)
    self._check_key("latitudeOfFirstGridPoint", 71676530)
    self._check_key("longitudeOfFirstGridPoint", 287218188)
    self._check_key("Dx", 2e9)
    self._check_key("Dy", 5e9)