code: function( model ) {
  			var coll =  _.detect( this._collections, function( c ) {
  					// Check if model is the type itself (a ref to the constructor), or is of type c.model
  					return model === c.model || model instanceof c.model;
  				});
  			
  			if ( !coll ) {
  				coll = this._createCollection( model );
  			}
  			
  			return coll;
  		}
docs: Find the Store's collection for a certain type of model.
  @param model {Backbone.RelationalModel}
  @return {Backbone.Collection} A collection if found (or applicable for 'model'), or null