syntax_data: {"ast_node_type":"impl","tokens":[{"end":66,"kind":"keyword","start":0,"text":")"}]}
source_snippet:     ) -> impl DoubleEndedIterator<Item = (Local, MovePathIndex)> {
context_before:         &self,
context_after:         self.locals.iter_enumerated().filter_map(|(l, &idx)| Some((l, idx?)))