code: void parseOption(String option) {
      if (option.isEmpty()) {
        return;
      }
  
      @SuppressWarnings("StringSplitter")
      String[] keyAndValue = option.split(SPLIT_KEY_VALUE);
      requireArgument(keyAndValue.length <= 2,
          "key-value pair %s with more than one equals sign", option);
  
      String key = keyAndValue[0].trim();
      String value = (keyAndValue.length == 1) ? null : keyAndValue[1].trim();
  
      configure(key, value);
    }
docs: Parses and applies the configuration option.