log.trace("Before replaceAsync3");
f3 = c1.replaceAsync(key, v_null, v6);
assert f3 != null;
assert !f3.isCancelled();
if (!isLockOwner(c1, key))
key.allowSerialization();
assertFutureValue(f3, false);
assert f3.isDone();
assertOnAllCaches(key, v5, c1, c2);
log.trace("Before replaceAsync4");