BUGFIX: never do std::printf(line), because it will try to parse embedded '%' characters as formatting characters, which leads to memory violations!!
BUGFIX: don't initialize the indexRange unless one is really given by the user. Some servers (e.g. Ignition by Inductive Automations) return a BadIndexRangeInvalid error when the index range is initialized as an empty string.
minor bugfix: the index range was not printed by toString()