public void setExpression(String expression) {
        this.expression = expression;
    }
<p>
The expression for the <code>TopicIRMetric</code>.
</p>

@param expression
       The expression for the <code>TopicIRMetric</code>.
aws-java-sdk-quicksight/src/main/java/com/amazonaws/services/quicksight/model/TopicIRMetric.java