django/tests/regressiontests/staticfiles_tests/storage.py

from datetime import datetime
from django.core.files import storage

class DummyStorage(storage.Storage):
    """
    A storage class that does implement modified_time() but raises
    NotImplementedError when calling
    """
    def _save(self, name, content):
        return 'dummy'

    def delete(self, name):
        pass

    def exists(self, name):
        pass

    def modified_time(self, name):
        return datetime.date(1970, 1, 1)