Subclasses that need to suspend the invocation of the next step until
 some condition is met (e.g. sending or receiving data has finished) need
 to override this method and create a <a href="../../../../de/esoco/coroutine/Suspension.html" title="class in de.esoco.coroutine"><code>Suspension</code></a> by invoking
 <a href="../../../../de/esoco/coroutine/Continuation.html#suspend-de.esoco.coroutine.CoroutineStep-de.esoco.coroutine.CoroutineStep-"><code>Continuation.suspend(CoroutineStep, CoroutineStep)</c