Can i set custom header when use ses sdk in java

[BaeEunshik]

When use smtp i can set header with method MimeMessage.setHeader

MimeMessage msg = new MimeMessage(session);
   msg.setHeader("CUSTOM","VALUE");

But i don't know how to set header With ses sdk (sesv2)

Below my code example

SesV2Client client = Sesv2Client.builder()
  .region(region) 
  .credentialsProvider(StaticCredentialsProvider.create(awsCred)
  .build();

...

SendEmailRequest emailReq = SendEmailRequest.builder()
  .destination(dest)
  .content(cont)
  .fromEmailAddress(sender)
  .build();

client.sendEmail(emailReq);

thank you