code: protected void addError(final DefaultDataSet ds, final String errorDesc, final int lineNo, final int errorLevel) {
          addError(ds, errorDesc, lineNo, errorLevel, null);
      }
docs: Adds a new error to this DataSet. These can be collected, and retrieved
  after processing
  
  @param ds
  the dataset
  @param errorDesc
  String description of error
  @param lineNo
  line number error occurred on
  @param errorLevel
  errorLevel 1,2,3 1=warning 2=error 3= severe error