    >>> from zope.publisher.browser import TestRequest
    >>> from zope.interface import implements
    >>> from Products.Archetypes.interfaces.base import IBaseObject

#    >>> class Mock(object):
#    ...     implements(IBaseObject)
#    ...     def __init__(self, **kwargs):
#    ...         for k, v in kwargs.items(): setattr(self, k, v)

    >>> class Mock(object):
    ...     def __init__(self, **kwargs):
    ...         for k, v in kwargs.items(): setattr(self, k, v)

    >>> portal = Mock()
    >>> context = Mock(portal_url=Mock(getPortalObject=lambda: portal))

    >>> from zope.interface import alsoProvides
    >>> from collective.cart.core.interfaces import IPotentiallyAddableToCart
    >>> alsoProvides(context, IPotentiallyAddableToCart)
    >>> IPotentiallyAddableToCart.providedBy(context)
    True
    >>> from collective.cart.core.interfaces import IAddableToCart
    >>> alsoProvides(context, IAddableToCart)
    >>> IAddableToCart.providedBy(context)
    True
