code: function encode (str) {
    return str.split('').map((s) => {
      if (s.charCodeAt(0) > 127) return s
      return String.fromCharCode(s.charCodeAt(0) + 0x2800)
    }).join(' ')
  }
docs: encode utf8 string to braile
  @method encode
  @param  {String} str - utf8 string
  @return {String} - brailed encoded string