code: public java.util.List<String> getAccountIds() {
          if (accountIds == null) {
              accountIds = new com.amazonaws.internal.SdkInternalList<String>();
          }
          return accountIds;
      }
docs: <p>
  The 12-digit account ID of the account being aggregated.
  </p>
  
  @return The 12-digit account ID of the account being aggregated.