presto-main/src/main/java/io/prestosql/operator/scalar/JsonStringToRowCast.java/JsonStringToRowCast/specialize
class JsonStringToRowCast:    @Override
    public ScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, Metadata metadata)
    {
        return JSON_TO_ROW.specialize(boundVariables, arity, metadata);
    }