Create this column family.

        For example:

        .. literalinclude:: snippets_table.py
            :start-after: [START bigtable_create_column_family]
            :end-before: [END bigtable_create_column_family]

def create(self):
        """Create this column family.

        For example:

        .. literalinclude:: snippets_table.py
            :start-after: [START bigtable_create_column_family]
            :end-before: [END bigtable_create_column_family]

        """
        column_family = self.to_pb()
        modification = table_admin_v2_pb2.ModifyColumnFamiliesRequest.Modification(
            id=self.column_family_id, create=column_family
        )

        client = self._table._instance._client
        # data it contains are the GC rule and the column family ID already
        # stored on this instance.
        client.table_admin_client.modify_column_families(
            self._table.name, [modification]
        )