code: @NonNull
      public Flowable<Changes> observeChangesOfUri(@NonNull Uri uri, @NonNull BackpressureStrategy backpressureStrategy) {
          return observeChangesOfUris(Collections.singleton(uri), backpressureStrategy);
      }
docs: Allows observe changes of required {@link Uri}.
  <p/>
  Notice, that returned {@link Flowable} is "Hot Flowable", it never ends, which means,
  that you should manually dispose from it to prevent memory leak.
  Also, it can cause BackPressure problems.
  
  @param uri {@link Uri} that should be monitored.
  @return {@link Flowable} of {@link Changes} subscribed to changes of required Uri.