code: public Observable<FileServerInner> getAsync(String resourceGroupName, String workspaceName, String fileServerName) {
          return getWithServiceResponseAsync(resourceGroupName, workspaceName, fileServerName).map(new Func1<ServiceResponse<FileServerInner>, FileServerInner>() {
              @Override
              public FileServerInner call(ServiceResponse<FileServerInner> response) {
                  return response.body();
              }
          });
      }
docs: Gets information about a File Server.
  
  @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 fileServerName The name of the file server within the specified resource group. File server names can only contain a combination of alphanumeric characters along with dash (-) and underscore (_). The name must be from 1 through 64 characters long.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the FileServerInner object