syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"lo_expr:"}]}
source_snippet:         lo_expr: Option<&'tcx hir::PatExpr<'tcx>>,
context_before:         &mut self,
context_after:         hi_expr: Option<&'tcx hir::PatExpr<'tcx>>,