assets/js/vendor/backbone-relational.js
function( relation ) {
			var exists = _.any( this._orphanRelations, function( rel ) {
				return _.all( relation || [], function( val, key ) {
					return val === rel[ key ];
				});
			});

			if ( !exists && relation.model && relation.type ) {
				this._orphanRelations.push( relation );
			}
		}
function( relation ) {
			var exists = _.any( this._orphanRelations, function( rel ) {
				return _.all( relation || [], function( val, key ) {
					return val === rel[ key ];
				});
			});

			if ( !exists && relation.model && relation.type ) {
				this._orphanRelations.push( relation );
			}
		}
Deposit a `relation` for which the `relatedModel` can't be resolved at the moment.

@param {Object} relation