assets/js/vendor/backbone-relational.js
function( relation ) {
			var coll = this.getCollection( relation.model, false );
			coll && coll.each( function( model ) {
				if ( !( model instanceof relation.model ) ) {
					return;
				}

				new relation.type( model, relation );
			}, this );
		}
function( relation ) {
			var coll = this.getCollection( relation.model, false );
			coll && coll.each( function( model ) {
				if ( !( model instanceof relation.model ) ) {
					return;
				}

				new relation.type( model, relation );
			}, this );
		}
Add a 'relation' to all existing instances of 'relation.model' in the store
@param {Object} relation