code: public ServiceFuture<ActivityInner> getAsync(String resourceGroupName, String automationAccountName, String moduleName, String activityName, final ServiceCallback<ActivityInner> serviceCallback) {
          return ServiceFuture.fromResponse(getWithServiceResponseAsync(resourceGroupName, automationAccountName, moduleName, activityName), serviceCallback);
      }
docs: Retrieve the activity in the module identified by module name and activity name.
  
  @param resourceGroupName Name of an Azure Resource group.
  @param automationAccountName The name of the automation account.
  @param moduleName The name of module.
  @param activityName The name of activity.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object