oking a <code>cancel(...)</code> method multiple times to cancel request processing has the same
 effect as canceling the request processing only once. Invoking a <code>cancel(...)</code> method on
 an asynchronous response instance that has already been cancelled or resumed has no effect and the
 method call is ignored while returning <code>true</code>, in case the request has been cancelled previously.
 Otherwise, in case the request has been resumed regularly (using a <code>resume(...) method</code>) or
