syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":".map(|(arm,"}]}
source_snippet:             .map(|(arm, branch)| {
context_before:             .zip(built_match_tree.branches)
context_after:                 debug!("lowering arm {:?}\ncorresponding branch = {:?}", arm, branch);