Buffer.prototype.append = function(buf) {
  var newBuf = new Buffer(this.length + buf.length);
  this.copy(newBuf, 0, 0);
  if (Buffer.isBuffer(buf))
    buf.copy(newBuf, this.length, 0);
  else if (Array.isArray(buf)) {
    for (var i=this.length, len=buf.length; i<len; i++)
      newBuf[i] = buf[i];
  }

  return newBuf;
};