public function setAttribute($attribute)
{
if (strpos($attribute, '.') !== false) {
$pieces = explode('.', $attribute, 2);
$this->setAlias($pieces[0]);
$attribute = $pieces[1];
// If an alias was already set then this must be set back to null.
} else {
$this->alias = null;
}
$this->attribute = $attribute;
}