{"ast_node_type":"variable","tokens":[{"end":73,"kind":"keyword","start":0,"text":"let"}]}
                let parent = self.infcx.tcx.parent_hir_node(expr.hir_id);
                let typeck = self.infcx.tcx.typeck(self.mir_def_id());
                let (def_id, call_id, args, offset) = if let hir::Node::Expr(parent_expr) = parent