syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"node.fn_sig().map_or(ty::Asyncness::No,"}]}
source_snippet:     node.fn_sig().map_or(ty::Asyncness::No, |sig| match sig.header.asyncness {
context_before:     let node = tcx.hir_node_by_def_id(def_id);
context_after:         hir::IsAsync::Async(_) => ty::Asyncness::Yes,