code: @Override
     @SuppressWarnings("unchecked")
     public final <T> T unwrap(Class<T> iface) throws SQLException
     {
        if (iface.isInstance(delegate)) {
           return (T) delegate;
        }
        else if (delegate != null) {
            return delegate.unwrap(iface);
        }
  
        throw new SQLException("Wrapped statement is not an instance of " + iface);
     }
docs: {@inheritDoc}