function (data) {
            if (!data) {
                return;
            }

            return _.union.apply(null, _.map(_.values(data), _.keys));
        }
function (data) {
            if (!data) {
                return;
            }

            return _.union.apply(null, _.map(_.values(data), _.keys));
        }
function ( data ) { if ( ! data ) { return ; } return _ . union . apply ( null , _ . map ( _ . values ( data ) , _ . keys ) ) ; }
Retrieves the keys provided by this layer object.

@param {Object} data the preference data from the Scope
Retrieves the keys provided by this layer object .
get a list of all the tables