Need help with a testing scenario: Document with a custom vocabulary field

Not sure what I'm missing, below is the beginning of a test I'm working on. Would appreciate pointers on what I've left out.

The goal is to

  1. define a vocabulary as part of a behaviour
  2. assign the new behavior to a document
  3. then run tests against the document with the vocabulary

Basically I want to be able to add the behaviour in my test suite. Something like this:

doc_with_customvocab = IDummyVocabField(doc)
# then add my tests below

Here is where I've reached (I know it's incomplete and broken, I'm sharing with the hope of getting some guidance)
note that, in "real life" you would register a behaviour using zcml, I'm avoiding that approach in the test.

def test_human_readable_title(self):
        self.assertEqual(len(self.collection.results()), 2)

        from zope.interface import implementer
        from zope.interface import Interface
        from import Document
        from plone.behavior.interfaces import IBehaviorAssignable
        from zope.component import adapter
        from zope.interface import implementer

        # define the vocabulary
        items = [ ('value1', u'Value 1 title'), ('value2', u'Value 2 title')]
        terms = [ SimpleTerm(value=pair[0], token=pair[0], title=pair[1]) for pair in items ]
        dummy_vocabulary = SimpleVocabulary(terms)

        # Field with a vocabulary
        class IDummyVocabField(model.Schema):
            dummy = schema.Choice(title=u"Dummy",

        # register field as a behavior
        from plone.behavior.registration import BehaviorRegistration
        from zope.component import provideAdapter
        registration = BehaviorRegistration(
               title=u"Dummy Vocab Field",
               description=u"Provides vocab field",

I think you'll need to register the registation as well.

from zope.component import provideUtility
provideUtility(registration, name=IDummyVocabField.__identifier__)

Alternatively you could try and see if you can call the behaviorDirective directly instead.

import plone.behavior.metaconfigure

  _context=[i dont know what goes in here],
title=u"Dummy Vocab Field",
description=u"Provides vocab field",

Thanks @jaroel,
Will look into this.