{"ast_node_type":"variable","tokens":[{"end":87,"kind":"keyword","start":0,"text":"let"}]}
                    let opt_label = self.lower_label(*opt_label, blk.id, block_hir_id);
                    let block_hir_id = self.lower_node_id(blk.id);
                    let hir_block = self.arena.alloc(self.lower_block_noalloc(