fn get_module<'a, 'b, Pos: SourcePos + 'a, MS: STeXModuleStore, Err: FnMut(String, SourceRange<Pos>, DiagnosticLevel)>(
p: &'b mut LaTeXParser<'a, ParseStr<'a, Pos>, STeXToken<Pos>, Err, STeXParseState<'a, Pos, MS>>,
) -> Option<(&'b ModuleURI, &'b mut Vec<ModuleRule<Pos>>)>