code: public void marshall(KeyMetadata keyMetadata, ProtocolMarshaller protocolMarshaller) {
  
          if (keyMetadata == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(keyMetadata.getAWSAccountId(), AWSACCOUNTID_BINDING);
              protocolMarshaller.marshall(keyMetadata.getKeyId(), KEYID_BINDING);
              protocolMarshaller.marshall(keyMetadata.getArn(), ARN_BINDING);
              protocolMarshaller.marshall(keyMetadata.getCreationDate(), CREATIONDATE_BINDING);
              protocolMarshaller.marshall(keyMetadata.getEnabled(), ENABLED_BINDING);
              protocolMarshaller.marshall(keyMetadata.getDescription(), DESCRIPTION_BINDING);
              protocolMarshaller.marshall(keyMetadata.getKeyUsage(), KEYUSAGE_BINDING);
              protocolMarshaller.marshall(keyMetadata.getKeyState(), KEYSTATE_BINDING);
              protocolMarshaller.marshall(keyMetadata.getDeletionDate(), DELETIONDATE_BINDING);
              protocolMarshaller.marshall(keyMetadata.getValidTo(), VALIDTO_BINDING);
              protocolMarshaller.marshall(keyMetadata.getOrigin(), ORIGIN_BINDING);
              protocolMarshaller.marshall(keyMetadata.getExpirationModel(), EXPIRATIONMODEL_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }
docs: Marshall the given parameter object.