docs: private ActionPatternHolder convertStringToPattern(String line) {
          ActionPatternHolder holder = new ActionPatternHolder();
          String[] strs = org.apache.commons.lang.StringUtils.split(line, "|");
          if (strs.length != 2) {
              throw new IllegalArgumentException("illegal expression: " + line);
          }
          Pattern compiledPattern;
          Perl5Compiler compiler = new Perl5Compiler();
          try {
              holder.setActionName(strs[0]);
              compiledPattern = compiler.compile(strs[0], Perl5Compiler.READ_ONLY_MASK);
              holder.setActionPattern(compiledPattern);
          } catch (MalformedPatternException mpe) {
              throw new IllegalArgumentException("Malformed regular expression: " + strs[0]);
          }
  
          try {
              holder.setMethodName(strs[1]);
              compiledPattern = compiler.compile(strs[1], Perl5Compiler.READ_ONLY_MASK);
              holder.setMethodPattern(compiledPattern);
          } catch (MalformedPatternException mpe) {
              throw new IllegalArgumentException("Malformed regular expression: " + strs[1]);
          }
  
          return holder;
      }