public void Then_ThrowsArgumentException()
 {
     EncryptUsing.SymmetricEncryptionProviderNamed(null);
 }
 public void Then_ThrowsArgumentException()
 {
     EncryptUsing.SymmetricEncryptionProviderNamed("provider")
     .UsingSharedSymmetricEncryptionInstanceNamed(null);
 }
 protected override void Act()
 {
     EncryptUsing.SymmetricEncryptionProviderNamed("symm instance provider name");
 }