code: protected String packagesRegExp() {
      StringBuilder	result;
      int			i;
      String		pkg;
  
      result = new StringBuilder();
      result.append(".* (");
      for (i = 0; i < m_Packages.size(); i++) {
        if (i > 0)
          result.append("|");
        pkg = m_Packages.get(i);
        if (!pkg.endsWith("."))
          pkg = pkg + ".";
        pkg = pkg.replace(".", "\\.");
        result.append(pkg);
      }
      result.append(").*$");
  
      return result.toString();
    }
docs: Builds the regular expression for the packages to keep.
  
  @return		the regexp