docs: public final String encode(byte[] bytes, int off, int len) {
      checkNotNull(bytes);
      checkPositionIndexes(off, off + len, bytes.length);
      CharOutput result = stringBuilderOutput(maxEncodedSize(len));
      ByteOutput byteOutput = encodingStream(result);
      try {
        for (int i = 0; i < len; i++) {
          byteOutput.write(bytes[off + i]);
        }
        byteOutput.close();
      } catch (IOException impossible) {
        throw new AssertionError("impossible");
      }
      return result.toString();
    }