syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"rev_lookup.un_derefer.insert(local,"}]}
source_snippet:                 rev_lookup.un_derefer.insert(local, reffed.as_ref());
context_after:                 let base_local = rev_lookup.un_derefer.deref_chain(local).first().unwrap().local;