code: public ServiceFuture<List<FileServerInner>> listByWorkspaceAsync(final String resourceGroupName, final String workspaceName, final FileServersListByWorkspaceOptions fileServersListByWorkspaceOptions, final ListOperationCallback<FileServerInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              listByWorkspaceSinglePageAsync(resourceGroupName, workspaceName, fileServersListByWorkspaceOptions),
              new Func1<String, Observable<ServiceResponse<Page<FileServerInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<FileServerInner>>> call(String nextPageLink) {
                      return listByWorkspaceNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }
docs: Gets a list of File Servers associated with the specified workspace.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param workspaceName The name of the workspace. Workspace names can only contain a combination of alphanumeric characters along with dash (-) and underscore (_). The name must be from 1 through 64 characters long.
  @param fileServersListByWorkspaceOptions Additional parameters for the operation
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object