code: function encodeBound(data, base) {
    var prefix = data.prefix
    var buffer = prefix ? base.encode(prefix, null) : new Buffer([ data.byte ])
  
    if (data.upper)
      buffer = Buffer.concat([ buffer, new Buffer([ 0xff ]) ])
  
    return util.encodedBound(data, buffer)
  }
docs: helpers for encoding boundary types