addRelationIs(rel) {
        if (!this.rel_is[rel.type])
            this.rel_is[rel.type] = [];
        this.rel_is[rel.type].push(rel);
    }
/**
     * Push a relation for non model Table, grouping by relation type
     * @param {Relation} rel 
     */
Push a relation for non model Table, grouping by relation type
@param {Relation} rel
Push a relation for non model Table grouping by relation type @param { Relation } rel
addRelationIs(rel) {
        if (!this.rel_is[rel.type])
            this.rel_is[rel.type] = [];
        this.rel_is[rel.type].push(rel);
    }
addRelationIs ( rel ) { if ( ! this . rel_is [ rel . type ] ) this . rel_is [ rel . type ] = [ ] ; this . rel_is [ rel . type ] . push ( rel ) ; }
Push a relation for non model Table, grouping by relation type
 @param {Relation} rel
Push a relation for non model Table grouping by relation type @param { Relation } rel