def METHOD_NAME(self, THUMBNAIL):
    """Tests that easy-thumbnails image field loads as expected."""
    THUMBNAIL.return_value = 'easy-thumbnails'
    # Reload fields to re-declare the DynamicImageField
    self.clear_imports()
    self.mock_easy_thumbnails_import()
    reload(fields)
    # Confirm inheritance from easy-thumbnails ThumbnailerImageField
    image_field = fields.DynamicImageField()
    self.assertEqual(image_field.parent_class, 'easy-thumbnails')