code: public java.util.List<String> getAddSubnetIds() {
          if (addSubnetIds == null) {
              addSubnetIds = new com.amazonaws.internal.SdkInternalList<String>();
          }
          return addSubnetIds;
      }
docs: <p>
  (Interface endpoint) One or more subnet IDs in which to serve the endpoint.
  </p>
  
  @return (Interface endpoint) One or more subnet IDs in which to serve the endpoint.