message: added a private constructor so users can only register, but not create new instances
diff: @@ -46,6 +46,8 @@ public class HybridEncryptWrapper implements PrimitiveWrapper<HybridEncrypt, Hyb
  }
  }
  + HybridEncryptWrapper() {}
  +
  @Override
  public HybridEncrypt wrap(final PrimitiveSet<HybridEncrypt> primitives) {
  return new WrappedHybridEncrypt(primitives);
  