docs: public void marshall(EmailMessage emailMessage, ProtocolMarshaller protocolMarshaller) {
  
          if (emailMessage == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(emailMessage.getBody(), BODY_BINDING);
              protocolMarshaller.marshall(emailMessage.getFeedbackForwardingAddress(), FEEDBACKFORWARDINGADDRESS_BINDING);
              protocolMarshaller.marshall(emailMessage.getFromAddress(), FROMADDRESS_BINDING);
              protocolMarshaller.marshall(emailMessage.getRawEmail(), RAWEMAIL_BINDING);
              protocolMarshaller.marshall(emailMessage.getReplyToAddresses(), REPLYTOADDRESSES_BINDING);
              protocolMarshaller.marshall(emailMessage.getSimpleEmail(), SIMPLEEMAIL_BINDING);
              protocolMarshaller.marshall(emailMessage.getSubstitutions(), SUBSTITUTIONS_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }