MockLock = function() {
  this.hasLock_ = false;
  this.id = Math.random();
  this.counter = 0;
}
@file Mocks out Apps Script's LockService.Lock. Does not implement
correct lock semantics at the moment. Previous versions relied on
node-fibers which is now obsolete. It's possible to recreate apps
script multi-threaded environment via worker threads and implement
proper locking and that may be considered in the future.