code: function(ext_guid, raw_properties, original_record) {
  
  		if (ext_guid in this._properties) Lava.t("MetaRecord already exists");
  
  		var properties = this._createRecordProperties(),
  			record = new this._record_constructor(this, this._fields, properties, raw_properties, original_record);
  
  		record.ext_guid = ext_guid;
  		this._records.push(record);
  		this._properties_by_guid[record.guid] = properties;
  		this._records_by_guid[record.guid] = record;
  
  		this._properties[ext_guid] = record;
  		this.firePropertyChangedEvents(ext_guid);
  
  		return record;
  
  	}
docs: Create a new MetaRecord instance
  @param {_tGUID} ext_guid GUID of the external record, to which this MetaRecord will be attached
  @param {Object} raw_properties Initial field values
  @param {Object} [original_record] Original record, which will be saved in MetaRecord instance
  @returns {Lava.data.MetaRecord}