code: func (p PublicKey) EncodeFixedWidth() []byte {
  	encoded := make([]byte, PublicKeyFixedWidthEncodingLength)
  	encoded[0] = p.CurveType.Byte()
  	copy(encoded[1:], p.PublicKey)
  	return encoded
  }
docs: // Produces a binary encoding of the CurveType byte plus
  // the public key for padded to a fixed width on the right