Comment 2 for bug 1642692

The protocol_id column doesn't have a direct reference to the federation_protocol table, instead, we have the following:

    migrate.ForeignKeyConstraint(
        columns=[federated_table.c.protocol_id, federated_table.c.idp_id],
        refcolumns=[protocol_table.c.id, protocol_table.c.idp_id]).create()