code: function unpackString(buffer, index=0, end=buffer.length) {
    return unpack(buffer, index, end);
  }
docs: Read a string of UTF-8 characters from a byte buffer.
  @param {!Uint8Array|!Array<number>} buffer A byte buffer.
  @param {number=} index The buffer index to start reading.
  @param {number=} end The buffer index to stop reading, non inclusive.
  Assumes buffer length if undefined.
  @return {string}