CCrmActivityRestProxy::innerGet

protected function innerGet($ID, &$errors)
{
	// Permissions will be checked by default
	$dbResult = CCrmActivity::GetList(array(), array('ID' => $ID));
	if($dbResult)
	{
		$result = $dbResult->Fetch();
		if ($result['PROVIDER_ID'] === \Bitrix\Crm\Activity\Provider\ConfigurableRestApp::getId())
		{
			$errors[] = 'Use crm.activity.configurable.get for this activity provider';

			return null;
		}

		return $result;
	}

	$errors[] = 'Activity is not found.';
	return null;
}