}

func (e *P521Element) bytes(out *[p521ElementLen]byte) []byte {
	var tmp p521NonMontgomeryDomainFieldElement
	p521FromMontgomery(&tmp, &e.x)
	p521ToBytes(out, (*p521UntypedFieldElement)(&tmp))
	p521InvertEndianness(out[:])
	return out[:]
}

// SetBytes sets e = v, where v is a big-endian 66-byte encoding, and returns e.
// If v is not 66 bytes or it encodes a value higher than 2^521 - 1,