lib/indexed_collection_mixin.js
function(models, options) {
    if(!models) return false;
    this.remove(models, options);
    var singular = !_.isArray(models);
    models = singular ? [models] : _.clone(models);
    return this._callAdapter('removeFromIndex', options, models);
  }
function(models, options) {
    if(!models) return false;
    this.remove(models, options);
    var singular = !_.isArray(models);
    models = singular ? [models] : _.clone(models);
    return this._callAdapter('removeFromIndex', options, models);
  }
function ( models , options ) { if ( ! models ) return false ; this . remove ( models , options ) ; var singular = ! _ . isArray ( models ) ; models = singular ? [ models ] : _ . clone ( models ) ; return this . _callAdapter ( 'removeFromIndex' , options , models ) ; }
Removes a model's key from index
@param {Array} models   model(s) whose keys (ids) are removed from index
@param {Object} options options
@returns {Promise} promise
Removes a model s key from index