code: function arrayOfArraysOfStrings(a, checkLowerCase) {
      return check.array(a) && a.every(function (arr) {
        return check.arrayOfStrings(arr, checkLowerCase);
      });
    }
docs: Returns true if given argument is array of arrays of strings
  @method arrayOfArraysOfStrings
  @param a Array to check
  @param checkLowerCase Checks if all strings are lowercase