The following happens when using {{mix}}:
(def c1 (to-chan (range 100 105)))
(def c2 (to-chan (range 10 15)))
(def mch (chan))
(def m (mix mch))
(admix m c1)
(admix m c2)
(toggle m {c1 {:pause true}})
=> true
(<!! mch)
=> 100
(<!! mch)
=> 101
(<!! mch)
=> 10
