TYPO3 Core

// check if extension can be fetched

if(isset($this->xmlhandler->extensionsXML[$extKey])) {

$versions = array_keys($this->xmlhandler->extensionsXML[$extKey]['versions']);

$latestVersion = end($versions);

switch($mode) {

case EM_INSTALL_VERSION_STRICT:

// Fetch extension from TER:

if(!strlen($version)) {

$versions = array_keys($this->xmlhandler->extensionsXML[$extKey]['versions']);

$version = end($versions);

}

$fetchData = $this->terConnection->fetchExtension($extKey, $version, $this->xmlhandler->extensionsXML[$extKey]['versions'][$version]['t3xfilemd5'], $this->getMirrorURL());