@NotNull public QueryBuilder append(@NotNull String sql,@NotNull Collection<?> args){
  query.append(requireNonNull(sql));
  addArguments(args);
  return this;
}

@ NotNull public QueryBuilder append ( @ NotNull String sql , @ NotNull Collection < ? > args ) { query . append ( requireNonNull ( sql ) ) ; addArguments ( args ) ; return this ; }
appends given fragment and arguments to this query .
