public PaymentAddress address()
{
IntPtr ptr_pa = SnarkDllApi.Key_SpendingKey_Address(this.ToArray());
byte[] by_a_pk = new byte[32];
byte[] by_pk_enc = new byte[32];
System.Runtime.InteropServices.Marshal.Copy(ptr_pa, by_a_pk, 0, 32);
System.Runtime.InteropServices.Marshal.Copy(ptr_pa + 32, by_pk_enc, 0, 32);
return(new PaymentAddress(new UInt256(by_a_pk), new UInt256(by_pk_enc)));
//return viewing_key().address();
}