syntax_data: {"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:             for (pos, sub_branch) in branch.sub_branches.into_iter().rev().with_position() {
context_before:             let target_block = self.cfg.start_new_block();
context_after:                 debug_assert!(pos != Position::Only);