public function toctouTest()
{
if (\ftell($this->fp) !== $this->pos) {
throw new CryptoException\FileModified('Read-only file has been modified since it was opened for reading');
}
$stat = \fstat($this->fp);
if ($stat['size'] !== $this->stat['size']) {
throw new CryptoException\FileModified('Read-only file has been modified since it was opened for reading');
}
}