syntax_data: {"ast_node_type":"variable","tokens":[{"end":69,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let kind = PeekCallKind::from_arg_ty(fn_args.type_at(0));
context_before:             assert_eq!(fn_args.len(), 1);
context_after:             let arg = match &args[0].node {