docs: static char[] toCharArray(final CharSequence cs) {
          if (cs instanceof String) {
              return ((String) cs).toCharArray();
          }
          final int sz = cs.length();
          final char[] array = new char[cs.length()];
          for (int i = 0; i < sz; i++) {
              array[i] = cs.charAt(i);
          }
          return array;
      }