code: @Override
      public <T> T unwrap(Class<T> paramClass)
      {
          try
          {
              return (T) this;
          }
          catch (ClassCastException ccex)
          {
              throw new PersistenceException("Provider does not support the call for class type:[" + paramClass + "]");
          }
      }
docs: /*
  (non-Javadoc)
  
  @see javax.persistence.Query#unwrap(java.lang.Class)