code: function(data) {
  		var key = hash_key(data[this.settings.valueField]);
  		if (typeof key === 'undefined' || key === null || this.options.hasOwnProperty(key)) return false;
  		data.$order = data.$order || ++this.order;
  		this.options[key] = data;
  		return key;
  	}
docs: Registers an option to the pool of options.
  
  @param {object} data
  @return {boolean|string}