toHex () {
    let out = ''
    for (let i = 0; i < this.length; i++) {
      let hexByte = this.getUInt8(i).toString(16)
      if (hexByte.length === 1) {
        hexByte = '0' + hexByte
      }
      out += hexByte
      if (i !== this.length - 1) {
        out += ' '
      }
    }
    return out
  }
Get string representation of buffer.
@return {string} Buffer as a string