code: public Observable<OperationStatus> deleteHierarchicalEntityChildAsync(UUID appId, String versionId, UUID hEntityId, UUID hChildId) {
          return deleteHierarchicalEntityChildWithServiceResponseAsync(appId, versionId, hEntityId, hChildId).map(new Func1<ServiceResponse<OperationStatus>, OperationStatus>() {
              @Override
              public OperationStatus call(ServiceResponse<OperationStatus> response) {
                  return response.body();
              }
          });
      }
docs: Deletes a hierarchical entity extractor child from the application.
  
  @param appId The application ID.
  @param versionId The version ID.
  @param hEntityId The hierarchical entity extractor ID.
  @param hChildId The hierarchical entity extractor child ID.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the OperationStatus object