syntax_data: {"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let subpattern = Box::new(Pat { span, ty, kind });
context_before:         for def_id in expanded_consts {
context_after:             kind = PatKind::ExpandedConstant { def_id, subpattern };