{"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"self.alloc_expr(Expr::Become"}]}
                self.alloc_expr(Expr::Become { expr }, syntax_ptr)
                    e.expr().map(|e| self.collect_expr(e)).unwrap_or_else(|| self.missing_expr());
            }