src/helpers/ExtensionDataHelper.php
public static function getOtherPackageData($data, $key, $asArray = false)
    {
        $out = null;
        if (false === empty($data[$key])) {
            $out = $data[$key];
        }
        if (true === $asArray) {
            $out = is_array($out) ? $out : [$out];
        } else {
            $out = is_array($out) ? implode(', ', $out) : $out;
        }
        return $out;
    }
public static function getOtherPackageData($data, $key, $asArray = false)
    {
        $out = null;
        if (false === empty($data[$key])) {
            $out = $data[$key];
        }
        if (true === $asArray) {
            $out = is_array($out) ? $out : [$out];
        } else {
            $out = is_array($out) ? implode(', ', $out) : $out;
        }
        return $out;
    }
Fetching data from defined field from for example installed.json file
data who has no 'versions' array inside
@param $data
@param $key
@param bool $asArray
@return array | string