public void setTraceId(String traceId) {
        this.traceId = traceId;
    }
<p>
The unique identifier for tracing the message. This identifier is visible to message recipients.
</p>

@param traceId
       The unique identifier for tracing the message. This identifier is visible to message recipients.
aws-java-sdk-pinpoint/src/main/java/com/amazonaws/services/pinpoint/model/MessageRequest.java