code: private void handleLongOptionWithEqual(String token) throws OptionParserException {
          int pos = token.indexOf('=');
          String name = token.substring(0, pos);
          String value = token.substring(pos + 1);
          List<String> matchingOpts = getMatchingLongOptions(name);
          if (matchingOpts.isEmpty()) {
              handleUnknownToken(currentToken);
          } else if (matchingOpts.size() > 1 && !options.hasLongOption(name)) {
              throw new AmbiguousOptionException(name, matchingOpts);
          } else {
              String key = (options.hasLongOption(name) ? name : matchingOpts.get(0));
              Option option = options.getOption(key);
              if (option.acceptsValue()) {
                  handleOption(option);
                  currentOption.addValue(value);
                  currentOption = null;
              } else {
                  handleUnknownToken(currentToken);
              }
          }
      }
docs: Handles the following tokens:
  <pre>
  --L=V
  -L=V
  --l=V
  -l=V
  </pre>
  
  @param token the command line token to handle
  @throws OptionParserException if option parsing fails