this ensures cleaner abstractions/code and will ensure that the produced
binary is as small as possible. a convenience package is provided to
easily load all hosts easily: "github.com/kidoman/embd/host/all"
this allows for the short version of the API to work as expected as
consecutive calls to the same pin would now be internally working on the
pin instance (all the 3 currently supported types). closing a pin busts
the cache