Merge "Use double-checked locking in (Java) Singleton type" into main

    }

    @UnsupportedAppUsage

    private T mInstance;

    private volatile T mInstance;

    protected abstract T create();

    @UnsupportedAppUsage

    public final T get() {

        T instance = mInstance;

        if (instance == null) {

            synchronized (this) {

                if (mInstance == null) {

                    mInstance = create();

                }

            return mInstance;

                instance = mInstance;

            }

        }

        return instance;

    }

}