function( model, coll, options ) {
			if ( ( this.keyId || this.keyId === 0 ) && model.id === this.keyId ) { // since 0 can be a valid `id` as well
				this.addRelated( model, options );
				this.keyId = null;
			}
		}
function( model, coll, options ) {
			if ( ( this.keyId || this.keyId === 0 ) && model.id === this.keyId ) { 
				this.addRelated( model, options );
				this.keyId = null;
			}
		}
function ( model , coll , options ) { if ( ( this . keyId || this . keyId === 0 ) && model . id === this . keyId ) { // since 0 can be a valid `id` as well this . addRelated ( model , options ) ; this . keyId = null ; } }
If a new 'this.relatedModel' appears in the 'store', try to match it to the last set 'keyContents'
If a new this . relatedModel appears in the store try to match it to the last set keyContents