code: public ServiceFuture<HostingEnvironmentDiagnosticsInner> getDiagnosticsItemAsync(String resourceGroupName, String name, String diagnosticsName, final ServiceCallback<HostingEnvironmentDiagnosticsInner> serviceCallback) {
          return ServiceFuture.fromResponse(getDiagnosticsItemWithServiceResponseAsync(resourceGroupName, name, diagnosticsName), serviceCallback);
      }
docs: Get a diagnostics item for an App Service Environment.
  Get a diagnostics item for an App Service Environment.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param name Name of the App Service Environment.
  @param diagnosticsName Name of the diagnostics item.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object