def compareItemVersion(item):
    if not 'VersionString' in item and 'CFBundleShortVersionString' in item:
        # Ensure that 'VersionString', if not present, is populated
        # with the value of 'CFBundleShortVersionString' if present
        item['VersionString'] = item['CFBundleShortVersionString']
    itemtype = item.get('type')
    if itemtype == 'application':
        return compareApplicationVersion(item)
    if itemtype == 'bundle':
        return compareBundleVersion(item)
    if itemtype == 'plist':
        return comparePlistVersion(item)
    if itemtype == 'file':
        return filesystemItemExists(item)
    raise munkicommon.Error('Unknown installs item type: %s', itemtype)
Compares an installs_item with what's on the startup disk.
dataset/ETHPy150Open munki/munki/code/client/munkilib/updatecheck.py/compareItemVersion