byobu: name a new session

byobu new -s <session-name>

Clojure: if key exists: update, otherwise: assoc

Source : if key exists: update, otherwise: assoc

user> (update {:a [1]} :a (fnil conj []) 2)
{:a [1 2]}
user> (update {:a [1]} :b (fnil conj []) 2)
{:a [1], :b [2]}