syntax_data: {"ast_node_type":"other","tokens":[{"end":31,"kind":"keyword","start":0,"text":"alts.push(alt);"}]}
source_snippet:                 alts.push(alt);
context_before:             (Self::Alt(mut alts), alt) | (alt, Self::Alt(mut alts)) => {
context_after:                 Self::Alt(alts)