keypair/main.go
func Parse(addressOrSeed string) (KP, error) {
	_, err := strkey.Decode(strkey.VersionByteAccountID, addressOrSeed)
	if err == nil {
		return &FromAddress{addressOrSeed}, nil
	}

	if err != strkey.ErrInvalidVersionByte {
		return nil, err
	}

	_, err = strkey.Decode(strkey.VersionByteSeed, addressOrSeed)
	if err == nil {
		return &Full{addressOrSeed}, nil
	}

	return nil, err
}
func Parse(addressOrSeed string) (KP, error) {
	_, err := strkey.Decode(strkey.VersionByteAccountID, addressOrSeed)
	if err == nil {
		return &FromAddress{addressOrSeed}, nil
	}

	if err != strkey.ErrInvalidVersionByte {
		return nil, err
	}

	_, err = strkey.Decode(strkey.VersionByteSeed, addressOrSeed)
	if err == nil {
		return &Full{addressOrSeed}, nil
	}

	return nil, err
}
// Parse constructs a new KP from the provided string, which should be either
// an address, or a seed.  If the provided input is a seed, the resulting KP
// will have signing capabilities.