code: public ActivityInner get(String resourceGroupName, String automationAccountName, String moduleName, String activityName) {
          return getWithServiceResponseAsync(resourceGroupName, automationAccountName, moduleName, activityName).toBlocking().single().body();
      }
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.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorResponseException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the ActivityInner object if successful.