Ordinarily, component-specific functions would reside in a component's
namespace, in this case that would be
`clojang.component.components.default-node`. However, since this entire
library is dedicated to managing a default Clojang node. those functions are
here, in the core namespace.

Since this library is strictly for managing a default node in a running
system, all functions take as their first parameter a system or component data
structure that has `:default-node` as a key.

If you wish to use the general Clojang functions for communicating with an
Erlang or Clojure node, you chould be using the clojang library directly.