mux 
Request routers.
- Route based on method:
http.Handle("/items", mux.Method{
"GET": getHandler,
"PUT": putHandler,
})
If no match return a 405 Method Not Allowed. A default implementation of
the OPTIONS method will return an Allow: ... header listing the defined
methods.
- Route based on
ContentType header:
http.Handle("/items", mux.ContentType{
"application/xml": xmlItemsGet,
"application/json": jsonItemsGet,
"*/*": itemsGet,
})
If no match return a 415 Unsupported Media Type.
- Route based on
Accept header:
http.Handle("/items", mux.Accept{
"application/xml": xmlItemsPut,
"application/json": jsonItemsPut,
"application/x-www-form-urlencoded": itemsPut,
})
If no match return a 406 Not Acceptable.