fn get_in_morphism<'b, MS: STeXModuleStore, Err: FnMut(String, SourceRange<LSPLineCol>, DiagnosticLevel)>(
groups: &'b mut Vec<STeXGroup<'_, MS, LSPLineCol, Err>>,
name: &str,
) -> Option<(&'b SymbolRule<LSPLineCol>, &'b mut VecMap<SymbolReference<LSPLineCol>, MorphismSpec<LSPLineCol>>)>