Function segment_url_query 

pub fn segment_url_query(
    mpd: &Mpd,
    period: &Period,
    set: &AdaptationSet,
    rep: &Representation,
    mpd_query: Option<&str>,
) -> Result<Option<String>, UrlQueryNotUnderstood>

The query to append to every Media Segment URL of rep (Annex I.2.3): Representation level, then AdaptationSet, Period, MPD, joined with &.

mpd_query is the query of the MPD’s own URL. None when no descriptor asks for one. An urn:mpeg:dash:urlparam:2016 property is not understood (callers treat an essential one as dropping the Representation, a supplemental one as ignored).

Errors

UrlQueryNotUnderstood for a @queryTemplate other than $querypart$.