def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
def _visit_migrate_unique_constraint(self, *p, **k):
    """Drop the given unique constraint

    The corresponding original method of sqlalchemy-migrate just
    raises NotImplemented error

    """

    self.recreate_table(p[0].table, omit_uniques=[p[0].name])