function _getTargetLineByThread(welThread){
            var sEndLineQuery = 'tr[data-line="' + welThread.data("range-endline") + '"]' +
                '[data-side="' + welThread.data("range-endside") + '"]';
            var welEndLine = welThread.closest("tr").prev(sEndLineQuery);

            return welEndLine;
        }
Get last line element in target range of comment-thread

@param welThread
@returns {*}
@private