syntax_data: {"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // Report error if there was one.
context_before:             let insert_result = sg.insert(tcx, impl_def_id.to_def_id(), overlap_mode);
context_after:             let (overlap, used_to_be_allowed) = match insert_result {