code: public String csvHeader() {
  
          if (m_csvItemFormatter != null) {
              return m_csvItemFormatter.csvHeader();
          } else {
              StringBuffer csv = new StringBuffer(1024);
              Iterator<CmsListColumnDefinition> itCols = m_columns.elementList().iterator();
              while (itCols.hasNext()) {
                  CmsListColumnDefinition col = itCols.next();
                  if (!col.isVisible()) {
                      continue;
                  }
                  csv.append(col.csvHeader());
                  csv.append("\t");
              }
              csv.append("\n\n");
              return csv.toString();
          }
      }
docs: Returns the csv output for the header of the list.<p>
  
  @return csv output