GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.

was the BEST butter, you know.'

  Alice had been looking over his shoulder with some curiosity.
`What a funny watch!' she remarked.  `It tells the day of the
month, and doesn't tell what o'clock it is!'

  `Why should it?' muttered the Hatter.  `Does YOUR watch tell
you what year it is?'

  `Of course not,' Alice replied very readily:  `but that's
because it stays the same year for such a long time together.'

             * corresponds to the least significant nonzero byte in lw ^ rw, since lw and rw are
             * little-endian. Long.numberOfTrailingZeros(diff) tells us the least significant
             * nonzero bit, and zeroing out the first three bits of L.nTZ gives us the shift to get
             * that least significant nonzero byte.
             */

   *
   * This has important consequences: it means that the RateLimiter doesn't remember the time of the
   * _last_ request, but it remembers the (expected) time of the _next_ request. This also enables
   * us to tell immediately (see tryAcquire(timeout)) whether a particular timeout is enough to get
   * us to the point of the next scheduling time, since we always maintain that. And what we mean by

            new AsyncCallable<String>() {
              @Override
              public ListenableFuture<String> call() throws Exception {
                // Make this executor terminate after this task so that the test can tell when
                // futureResult has received resultOfCombiner.
                executor.shutdown();
                callableBlocking.await();
                return resultOfCombiner;
              }

            new AsyncCallable<String>() {
              @Override
              public ListenableFuture<String> call() throws Exception {
                // Make this executor terminate after this task so that the test can tell when
                // futureResult has received resultOfCombiner.
                executor.shutdown();
                callableBlocking.await();
                return resultOfCombiner;
              }

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

    Our workaround is to tell GWT that util.concurrent and all other packages
    have prod supersource, even if they have none. GWT is happy to ignore us
    when we specify a nonexistent path.