def METHOD_NAME(self, app):
    fi_req = '/wmts/myrest/wms_cache/GLOBAL_MERCATOR/00/0/0/17/27.gml'
    serv = MockServ(port=42423)
    serv.expects(
        "/service?layers=foo,bar"
        + "&bbox=-20037508.342789244,-20037508.342789244,20037508.342789244,20037508.342789244"
        + "&width=256&height=256&x=17&y=27&query_layers=foo,bar&format=image%2Fpng&srs=EPSG%3A900913"
        + "&request=GetFeatureInfo&version=1.1.1&service=WMS&styles=&info_format=application/gml%2bxml%3b%20version=3.1"
    )
    serv.returns(b"<root />")
    with serv:
        resp = app.get(str(fi_req), status=200)
        assert resp.headers["Content-type"] == "application/gml+xml; version=3.1"