code: public void marshall(Action action, ProtocolMarshaller protocolMarshaller) {
  
          if (action == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(action.getDynamoDB(), DYNAMODB_BINDING);
              protocolMarshaller.marshall(action.getDynamoDBv2(), DYNAMODBV2_BINDING);
              protocolMarshaller.marshall(action.getLambda(), LAMBDA_BINDING);
              protocolMarshaller.marshall(action.getSns(), SNS_BINDING);
              protocolMarshaller.marshall(action.getSqs(), SQS_BINDING);
              protocolMarshaller.marshall(action.getKinesis(), KINESIS_BINDING);
              protocolMarshaller.marshall(action.getRepublish(), REPUBLISH_BINDING);
              protocolMarshaller.marshall(action.getS3(), S3_BINDING);
              protocolMarshaller.marshall(action.getFirehose(), FIREHOSE_BINDING);
              protocolMarshaller.marshall(action.getCloudwatchMetric(), CLOUDWATCHMETRIC_BINDING);
              protocolMarshaller.marshall(action.getCloudwatchAlarm(), CLOUDWATCHALARM_BINDING);
              protocolMarshaller.marshall(action.getElasticsearch(), ELASTICSEARCH_BINDING);
              protocolMarshaller.marshall(action.getSalesforce(), SALESFORCE_BINDING);
              protocolMarshaller.marshall(action.getIotAnalytics(), IOTANALYTICS_BINDING);
              protocolMarshaller.marshall(action.getIotEvents(), IOTEVENTS_BINDING);
              protocolMarshaller.marshall(action.getStepFunctions(), STEPFUNCTIONS_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }
docs: Marshall the given parameter object.