This list not sorted!
$versions = array_keys($this->xmlhandler->extensionsXML[$extKey]['versions']);
$latestVersion = end($versions);

On line: 1610,1735,1382......

User this sort Function from Elmar Hinz:

Own 
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Sort: 
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  usort($versions, array('SC_mod_tools_em_index', 'compare'));
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Function:
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	function compare($aIn, $bIn) {
		$aParts = explode('.', $aIn, 2);
		$bParts = explode('.', $bIn, 2);
		$a = (int) $aParts[0];
		$b = (int) $bParts[0];
		if($a > $b){
			return 1;
		}elseif($a < $b){
			return -1;
		} else {
			if(is_string($aParts[1])) {
					return SC_mod_tools_em_index::compare($aParts[1], $bParts[1]);
			} else {
				return 0;
			}
		}
	}
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regards Micha Barthel