docs: function(props){
  		var keys = Object.keys(this.clauses.id);
  		if(keys.length === 1) {
  			return props[keys[0]];
  		} else {
  			var id = {};
  			keys.forEach(function(key){
  				id[key] = props[key];
  			});
  			return JSON.stringify(id);
  		}
  	}