public function removeSystemFields()
{
$properties = $this->fields;
unset($properties['created'], $properties['changed'], $properties['changer'], $properties['changer_id'], $properties['creator'], $properties['creator_id']);
foreach ($properties as $key => $field) {
// remove system fields
if (substr($key, 0, 2) == '__') {
continue;
}
$this->properties[$key] = $field->getValue();
}
}