class ECKey implements Serializable {

    @Nullable
    public byte[] getPrivKeyBytes() {
        if (privKey == null) {
            return null;
        } else if (privKey instanceof BCECPrivateKey) {
            return bigIntegerToBytes(((BCECPrivateKey) privKey).getD(), 32);
        } else {
            return null;
        }
    }

    public  ECKey();
    public  ECKey(Provider provider, SecureRandom secureRandom);
    public  ECKey(SecureRandom secureRandom);
    public  ECKey(Provider provider, @Nullable PrivateKey privKey, ECPoint pub);
    public  ECKey(@Nullable BigInteger priv, ECPoint pub);

}