Return ``True`` if the container can be safely extracted,
        that is, if all its entries are safe, ``False`` otherwise.

        :rtype: bool
        :raises: same as :func:`~aeneas.container.Container.entries`

def is_safe(self):
        """
        Return ``True`` if the container can be safely extracted,
        that is, if all its entries are safe, ``False`` otherwise.

        :rtype: bool
        :raises: same as :func:`~aeneas.container.Container.entries`
        """
        self.log(u"Checking if this container is safe")
        for entry in self.entries:
            if not self.is_entry_safe(entry):
                self.log([u"This container is not safe: found unsafe entry '%s'", entry])
                return False
        self.log(u"This container is safe")
        return True