// deflate: recklessly assumes contents are PBF.
} else if (buffer[0] === 0x78 && buffer[1] === 0x9C) {
    return 'pbf';
// gzip: recklessly assumes contents are PBF.
} else if (buffer[0] === 0x1F && buffer[1] === 0x8B) {
    return 'pbf';
// encoding popular in charlbury
} else if (buffer[0] === 0x62 && buffer[1] === 0x61 && buffer[2] === 0x6e &&
  buffer[3] === 0x20 && buffer[4] === 0x6d && buffer[5] === 0x61 &&
  buffer[6] === 0x70 && buffer[7] === 0x62 && buffer[8] === 0x6f &&
  buffer[9] === 0x78 && buffer[10] === 0x21) {
    return 'pbf';
}
return false;