Return the music service item that corresponds to xml.

    The class is identified by getting the type from the 'itemType' tag

def get_ms_item(xml, service, parent_id):
    """Return the music service item that corresponds to xml.

    The class is identified by getting the type from the 'itemType' tag
    """
    cls = MS_TYPE_TO_CLASS.get(xml.findtext(ns_tag('ms', 'itemType')))
    out = cls.from_xml(xml, service, parent_id)
    return out