syntax_data: {"ast_node_type":"variable","tokens":[{"end":51,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let ns = guess_def_namespace(self, def_id);
context_before:         let def_id = def_id.into_query_param();
context_after:         debug!("value_path_str: def_id={:?}, ns={:?}", def_id, ns);