Function load_from_str_labeled 

pub fn load_from_str_labeled(
    content: &str,
    source: &str,
) -> Result<usize, String>

Load a dump, naming source (a real path or an <embedded TLyyyy> label) in the single dump_reader:loaded Info line. The dump wrappers (plain_dump/latex_dump) use this so there is exactly ONE “loaded N entries from ” message per dump — they no longer emit a second, redundant *_dump:loaded line of their own.