My premium theme came with a bundled version of Metabox and it's working well. It is installed as part of a separate plugin that contains many of the themes features. Basically:
Theme: ACME Theme
Plugin: ACME Theme Functionality (contains Metabox)
I'm creating a custom plugin to add some additional features to my website, and I want to use Metabox in that as well since I already have it installed.
What is the correct way to allow my custom plugin to hook into the bundled version of Metabox that's part of that other theme plugin?