public function validate($vatNumber)
{
if (strlen($vatNumber) != 8) {
return false;
}
$weights = array(2, 7, 6, 5, 4, 3, 2, 1);
$checksum = $this->sumWeights($weights, $vatNumber);
if ($checksum % 11 > 0) {
return false;
}
return true;
}