code: public Observable<ProjectTaskInner> updateAsync(String groupName, String serviceName, String projectName, String taskName, ProjectTaskInner parameters) {
          return updateWithServiceResponseAsync(groupName, serviceName, projectName, taskName, parameters).map(new Func1<ServiceResponse<ProjectTaskInner>, ProjectTaskInner>() {
              @Override
              public ProjectTaskInner call(ServiceResponse<ProjectTaskInner> response) {
                  return response.body();
              }
          });
      }
docs: Create or update task.
  The tasks resource is a nested, proxy-only resource representing work performed by a DMS instance. The PATCH method updates an existing task, but since tasks have no mutable custom properties, there is little reason to do so.
  
  @param groupName Name of the resource group
  @param serviceName Name of the service
  @param projectName Name of the project
  @param taskName Name of the Task
  @param parameters Information about the task
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the ProjectTaskInner object