public synchronized void close() {
    if (mAccountDb != null) {
      mAccountDb.close();
    }

    mContext = null;
    mAccountDb = null;
    mStartActivityListener = null;
    mStartServiceListener = null;
  }
Closes any resources and objects held by this module. The module cannot be used after this
operation.
java/com/google/android/apps/authenticator/testability/DependencyInjectorModule.java