static isStringArray (arr, minLen = 1) {
    if (!Array.isArray(arr)) {
      return false;
    }

    for (const str of arr) {
      if (typeof str !== 'string' || str.length < minLen) {
        return false;
      }
    }
    return true;
  }
Is arr an array of strings, with each string being at least minLen