        . fmap (compositeValue *>) getNonNullable
    {-# INLINE getRowNullValue #-}
    getRowNullValue = CompositeValue
        . fmap (compositeValue *>) getNullable
    {-# INLINE runRowDecoder #-}
    runRowDecoder = unCompositeValue

instance  (PrimField a1, PrimField a2, PrimField a3)
    => PrimField (a1, a2, a3) where
