Parse metadata returned from the metadataUrl of a USGS scene.

    :param scene:
        Dictionary representation of a USGS scene
    :param resp:
        Response object from requests/grequests

def _get_extended(scene, resp):
    """
    Parse metadata returned from the metadataUrl of a USGS scene.

    :param scene:
        Dictionary representation of a USGS scene
    :param resp:
        Response object from requests/grequests
    """
    root = ElementTree.fromstring(resp.text)
    items = root.findall("eemetadata:metadataFields/eemetadata:metadataField", NAMESPACES)
    scene['extended'] = {item.attrib.get('name').strip(): xsi.get(item[0]) for item in items}

    return scene