code: public Observable<ServiceResponse<PersistedFace>> addFaceFromUrlWithServiceResponseAsync(String faceListId, String url, AddFaceFromUrlOptionalParameter addFaceFromUrlOptionalParameter) {
          if (this.client.azureRegion() == null) {
              throw new IllegalArgumentException("Parameter this.client.azureRegion() is required and cannot be null.");
          }
          if (faceListId == null) {
              throw new IllegalArgumentException("Parameter faceListId is required and cannot be null.");
          }
          if (url == null) {
              throw new IllegalArgumentException("Parameter url is required and cannot be null.");
          }
          final String userData = addFaceFromUrlOptionalParameter != null ? addFaceFromUrlOptionalParameter.userData() : null;
          final List<Integer> targetFace = addFaceFromUrlOptionalParameter != null ? addFaceFromUrlOptionalParameter.targetFace() : null;
  
          return addFaceFromUrlWithServiceResponseAsync(faceListId, url, userData, targetFace);
      }
docs: Add a face to a face list. The input face is specified as an image with a targetFace rectangle. It returns a persistedFaceId representing the added face, and persistedFaceId will not expire.
  
  @param faceListId Id referencing a particular face list.
  @param url Publicly reachable URL of an image
  @param addFaceFromUrlOptionalParameter the object representing the optional parameters to be set before calling this API
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PersistedFace object