code: public boolean isHelpSetFile(String fileName) {
          if (helpSetFilter == null) {
              helpSetFilter = new WildcardFileFilter(helpSetPattern);
          }
          
          return helpSetFilter.accept(new File(fileName));
      }
docs: Returns true if the file name matches the pattern specified for the main help set file.
  
  @param fileName File name to check.
  @return True if this is the main help set file.