code: public ElasticLoadBalancer withEc2InstanceIds(String... ec2InstanceIds) {
          if (this.ec2InstanceIds == null) {
              setEc2InstanceIds(new com.amazonaws.internal.SdkInternalList<String>(ec2InstanceIds.length));
          }
          for (String ele : ec2InstanceIds) {
              this.ec2InstanceIds.add(ele);
          }
          return this;
      }
docs: <p>
  A list of the EC2 instances that the Elastic Load Balancing instance is managing traffic for.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setEc2InstanceIds(java.util.Collection)} or {@link #withEc2InstanceIds(java.util.Collection)} if you want
  to override the existing values.
  </p>
  
  @param ec2InstanceIds
  A list of the EC2 instances that the Elastic Load Balancing instance is managing traffic for.
  @return Returns a reference to this object so that method calls can be chained together.