code: function getRemoveIndexes ( modelsToRemove, models ) {
          var indexes = {},
              toRemove = modelsToRemove || [];
  
          if( !_.isArray( toRemove ) ) toRemove = [toRemove];
  
          models = models.slice() || [];
  
          _.each( toRemove, function ( model ) {
              var index = _.indexOf( models, model );
              if ( index !== -1 ) {
                  indexes[model.cid] = index;
                  models.splice( index, 1 );
              }
          } );
  
          return indexes;
      }
docs: Helpers for patchSilent*