public Message withSubject(Content subject) {
        setSubject(subject);
        return this;
    }
<p>
The subject of the message: A short summary of the content, which appears in the recipient's inbox.
</p>

@param subject
       The subject of the message: A short summary of the content, which appears in the recipient's inbox.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-ses/src/main/java/com/amazonaws/services/simpleemail/model/Message.java