public MessageInsightsFilters withSubject(String... subject) {
        if (this.subject == null) {
            setSubject(new java.util.ArrayList<String>(subject.length));
        }
        for (String ele : subject) {
            this.subject.add(ele);
        }
        return this;
    }
<p>
The subject line of the message.
</p>
<p>
<b>NOTE:</b> This method appends the values to the existing list (if any). Use
{@link #setSubject(java.util.Collection)} or {@link #withSubject(java.util.Collection)} if you want to override
the existing values.
</p>

@param subject
       The subject line of the message.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-sesv2/src/main/java/com/amazonaws/services/simpleemailv2/model/MessageInsightsFilters.java