Furthermore not all test cannot be passed if one or more layers are not provided by the external service.
The ETS should be independent of an external service or at least the URLs must be checked. Furthermore the available Layers should be parsed from the Capabilities.
This ETS depends on external WMS. On of three hardcoded WMS are used, if all of them are unavailable a test run fails. The WMS URL is selected here: https://github.com/opengeospatial/ets-wms-client13/blob/d8f5c6162d55c49e1d6209d9ba4e016547ce169d/src/main/scripts/ctl/main.ctl#L44-L54
Furthermore not all test cannot be passed if one or more layers are not provided by the external service.
The ETS should be independent of an external service or at least the URLs must be checked. Furthermore the available Layers should be parsed from the Capabilities.