Same as `defn`, but will automatically add an n-1 arity,
where the first argument (local-device-id) can be omited. For
example, given the following arguments, it will create a new arity :
[local-device-id remote-device-id] -> [remote-device-id].

This is intended to make it easier to use the functions at the REPL
when working with a single local-device.

Given some symbols, construct a map with the symbols as keys, and
the value of the symbols as the map values. For example:
(Let [aa 12]
   (mapify aa))
=> {:aa 12}

Blocks until predicate returns false, or throws if timeout.