code: @Override
      public ListCoreDefinitionsResult listCoreDefinitions(ListCoreDefinitionsRequest request) {
          request = beforeClientExecution(request);
          return executeListCoreDefinitions(request);
      }
docs: Retrieves a list of core definitions.
  
  @param listCoreDefinitionsRequest
  @return Result of the ListCoreDefinitions operation returned by the service.
  @sample AWSGreengrass.ListCoreDefinitions
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/greengrass-2017-06-07/ListCoreDefinitions" target="_top">AWS
  API Documentation</a>