syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"ExpnKind::AstPass(kind)"}]}
source_snippet:             ExpnKind::AstPass(kind) => kind.descr().to_string(),
context_before:             },
context_after:             ExpnKind::Desugaring(kind) => format!("desugaring of {}", kind.descr()),