@staticmethod
def merge_extinfo(host, extinfo):
    """Merge extended host information into a host

        :param host: the host to edit
        :type host: alignak.objects.host.Host
        :param extinfo: the external info we get data from
        :type extinfo: alignak.objects.hostextinfo.HostExtInfo
        :return: None
        """
    properties = ['notes', 'notes_url', 'icon_image', 'icon_image_alt',
        'vrml_image', 'statusmap_image']
    for prop in properties:
        if getattr(host, prop) == '' and getattr(extinfo, prop) != '':
            setattr(host, prop, getattr(extinfo, prop))
