public IngressStringToEvaluate withAttribute(IngressStringEmailAttribute attribute) {
        this.attribute = attribute.toString();
        return this;
    }
<p>
The enum type representing the allowed attribute types for a string condition.
</p>

@param attribute
       The enum type representing the allowed attribute types for a string condition.
@return Returns a reference to this object so that method calls can be chained together.
@see IngressStringEmailAttribute
aws-java-sdk-mailmanager/src/main/java/com/amazonaws/services/mailmanager/model/IngressStringToEvaluate.java