def _reload(self, columns):

        # set the primary key flag on new columns.
        # note any existing PK cols on the table also have their
        # flag still set.
        for col in columns:
            col.primary_key = True

        self.columns.extend(columns)

        self._set_parent_with_dispatch(self.table)
Checks if the clustering is already inside 'all_clusterings', returning a rejection reason in this case.
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/sql/schema.py/PrimaryKeyConstraint._reload--crossover with--dataset/ETHPy150Open victor-gil-sepulveda/pyProCT/pyproct/clustering/filtering/clusteringFilter.py/ClusteringFilter.filter_repeated