public void setInstanceArns(java.util.Collection<String> instanceArns) {
        if (instanceArns == null) {
            this.instanceArns = null;
            return;
        }

        this.instanceArns = new java.util.ArrayList<String>(instanceArns);
    }
<p>
The Amazon Resource Name (ARN) of the instances for which to return recommendations.
</p>

@param instanceArns
       The Amazon Resource Name (ARN) of the instances for which to return recommendations.
aws-java-sdk-computeoptimizer/src/main/java/com/amazonaws/services/computeoptimizer/model/GetEC2InstanceRecommendationsRequest.java