code: function defaultValue (key) {
      if (!checkAllAliases(key, flags.bools) &&
          !checkAllAliases(key, flags.counts) &&
          `${key}` in defaults) {
        return defaults[key]
      } else {
        return defaultForType(guessType(key))
      }
    }
docs: make a best effor to pick a default value for an option based on name and type.