syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":"assert_eq!(args.len(),"}]}
source_snippet:         assert_eq!(args.len(), 1);
context_before:         let args = GenericArgs::identity_for_item(tcx, def_id);
context_after:         let result = DropckConstraint {