UserModel::isAdmin

public function isAdmin(): bool
{
	if (!$this->userId)
	{
		return false;
	}
	if ($this->isAdmin === null)
	{
		$currentUser = CurrentUser::get();
		if ((int) $currentUser->getId() === $this->userId)
		{
			$userGroups = $currentUser->getUserGroups();
		}
		else
		{
			$userGroups = CUser::GetUserGroup($this->userId);
		}
		$this->isAdmin = in_array(1, $userGroups);
	}
	return $this->isAdmin;
}