public void setVariables(java.util.Collection<ExpressionVariable> variables) {
        if (variables == null) {
            this.variables = null;
            return;
        }

        this.variables = new java.util.ArrayList<ExpressionVariable>(variables);
    }
<p>
The list of variables used in the expression.
</p>

@param variables
       The list of variables used in the expression.
aws-java-sdk-iotsitewise/src/main/java/com/amazonaws/services/iotsitewise/model/Metric.java