Thanks for the proposition!
But with that, the sorting does not take MediaRange in consideration, doesn't it?

The test is then not successful anymore:
```
[info] a Request Header should
[error] x compute the accepted types sorted by preference (preferred first)
[error]    List(MediaRange(text,json,None), MediaRange(text,html,Some(level=2)), MediaRange(text,html,Some(level=1)), MediaRange(text,html,None), MediaRange(text,*,None), MediaRange(*,*,None))
[error]     is not equal to 
[error]    List(MediaRange(text,html,Some(level=1)), MediaRange(text,html,None), MediaRange(*,*,None), MediaRange(text,html,Some(level=2)), MediaRange(text,json,None), MediaRange(text,*,None)) (RequestHeaderSpec.scala:25)
[error] Expected: ...text,[html],[S]o[m]e[(level=1])[)], ...l,[N]o[n]e[), M]e[diaRang]e[(*,*,None]),...l=[2]))...t,[json],N...e)[])[]
[error] Actual:   ...text,[json],[N]o[n]e[])[], ...l,[S]o[m]e[(l]e[v]e[l=2)]),...l=[1]))...t,[html],N...e)[, MediaRange(*,*,None])[)]
```