'Get a BlobInfo value, loading entity if necessary.
This method allows lazy loading of the underlying datastore entity.  It
should never be invoked directly.
Args:
name: Name of property to get value for.
Returns:
Value of BlobInfo property from entity.'

def __get_value(self, name):

    if (self.__entity is None):
        self.__entity = datastore.Get(datastore_types.Key.from_path(self.kind(), str(self.__key), namespace=''))
    try:
        return self.__entity[name]
    except KeyError:
        raise AttributeError(name)
