@Override
    public void failed(Throwable t) {
        completeExceptionally(t);
    }
<p>This class provides an implementation of {@link CompletionHandler} that allows you to wait for either {@link
#completed()} or {@link #failed(Throwable)} to be called. If failed() was called, the corresponding Throwable will
be rethrown when calling either of the get() methods. Unless an exception is thrown, the get() methods will always
return Boolean.TRUE.</p>

<p>Notice that calling {@link #cancel(boolean)} throws an UnsupportedOperationException.</p>

@author Simon Thoresen Hult
jdisc_core/src/main/java/com/yahoo/jdisc/handler/FutureCompletion.java