code: @Override
      public ListDeviceDefinitionsResult listDeviceDefinitions(ListDeviceDefinitionsRequest request) {
          request = beforeClientExecution(request);
          return executeListDeviceDefinitions(request);
      }
docs: Retrieves a list of device definitions.
  
  @param listDeviceDefinitionsRequest
  @return Result of the ListDeviceDefinitions operation returned by the service.
  @sample AWSGreengrass.ListDeviceDefinitions
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/greengrass-2017-06-07/ListDeviceDefinitions"
  target="_top">AWS API Documentation</a>