[O] check if properties drawer exists before creating or manipulating?

[Matt Price]

(still trying to set properties automatically when a minor-mode is
set, see first message in thread)

Is there a simple way to check if the properties drawer exists before
creating one?
I'm trying to add a hook to org-insert-heading-hook that will create a
property drawer if one doesn't exist; I don't want to create a bunch
of independent properties drawers.

Thanks!

Matt