syntax_data: {"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let Some(output) = tcx.hir_get_fn_output(fn_def_id) else {
context_before:                 let fn_def_id = item.owner_id.def_id;
context_after:                     return Some((fn_def_id.to_def_id(), vec![]));