e.setValueReference(valueReference);
            recordWrite(e, 0, now); // no change in weight
            return newValue;
          }
          try {
            return getAndRecordStats(key, hash, computingValueReference, immediateFuture(newValue));
          } catch (ExecutionException exception) {
            throw new AssertionError("impossible; Futures.immediateFuture can't throw");
          }