def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def image_url(self, name, override_receipt_id=None):
        """
        We dynamically generate this, since we want it the expiration clock to
        start when the message is created, not when the record is created.

        Arguments:
            name (str): Name of the image (e.g. "photo_id" or "face")

        Keyword Arguments:
            override_receipt_id (str): If provided, use this receipt ID instead
                of the ID for this attempt.  This is useful for reverification
                where we need to construct a URL to a previously-submitted
                photo ID image.

        Returns:
            string: The expiring URL for the image.

        """
        path = self._get_path(name, override_receipt_id=override_receipt_id)
        return self._storage.url(path)