code: public void setEc2InstanceIds(java.util.Collection<String> ec2InstanceIds) {
          if (ec2InstanceIds == null) {
              this.ec2InstanceIds = null;
              return;
          }
  
          this.ec2InstanceIds = new com.amazonaws.internal.SdkInternalList<String>(ec2InstanceIds);
      }
docs: <p>
  A list of the EC2 instances that the Elastic Load Balancing instance is managing traffic for.
  </p>
  
  @param ec2InstanceIds
  A list of the EC2 instances that the Elastic Load Balancing instance is managing traffic for.