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# We would be using django.utils.functional.cached_property, except it
# breaks when used with mox in our tests, because of
# https://code.djangoproject.com/ticket/19872
#
# So we have a copy of it here, with the bug fixed.
# FIXME: Use django's version when the bug is fixed there.
class cached_property(object):
    """Decorator that creates converts a method with a single self argument
    into a property cached on the instance.
    """

    def __init__(self, func):
        self.func = func

    def __get__(self, instance, type):
        if instance is None:
            return self
        res = instance.__dict__[self.func.__name__] = self.func(instance)
        return res
