docs: public Observable<String> beginReplaceContentAsync(String resourceGroupName, String automationAccountName, String runbookName, String runbookContent) {
          return beginReplaceContentWithServiceResponseAsync(resourceGroupName, automationAccountName, runbookName, runbookContent).map(new Func1<ServiceResponseWithHeaders<String, RunbookDraftReplaceContentHeaders>, String>() {
              @Override
              public String call(ServiceResponseWithHeaders<String, RunbookDraftReplaceContentHeaders> response) {
                  return response.body();
              }
          });
      }