code: private final void setto(String s) {
          int l = s.length();
          int o = j + 1;
          for (int i = 0; i < l; i++) {
              b[o + i] = s.charAt(i);
          }
          k = j + l;
      }
docs: Sets (j+1),...k to the characters in the string s, readjusting k.