CAllUser::GetByID

static function GetByID($ID)
{
	global $USER;

	$ID = intval($ID);

	if ($ID < 1)
	{
		//actually, here should be an exception
		$rs = new CDBResult;
		$rs->InitFromArray([]);
		return $rs;
	}

	$userID = (is_object($USER) ? intval($USER->GetID()) : 0);
	if ($userID > 0 && $ID == $userID && is_array(self::$CURRENT_USER))
	{
		$rs = new CDBResult;
		$rs->InitFromArray(self::$CURRENT_USER);
	}
	else
	{
		$rs = static::GetList('id', 'asc', ["ID_EQUAL_EXACT" => intval($ID)], ["SELECT" => ["UF_*"]]);
		if ($userID > 0 && $ID == $userID)
		{
			self::$CURRENT_USER = [$rs->Fetch()];
			$rs = new CDBResult;
			$rs->InitFromArray(self::$CURRENT_USER);
		}
	}
	return $rs;
}