code: public java.util.List<String> getRdsDbInstanceArns() {
          if (rdsDbInstanceArns == null) {
              rdsDbInstanceArns = new com.amazonaws.internal.SdkInternalList<String>();
          }
          return rdsDbInstanceArns;
      }
docs: <p>
  An array containing the ARNs of the instances to be described.
  </p>
  
  @return An array containing the ARNs of the instances to be described.