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 _get_markup_for_tags(self, tag_names):
        """Given a list of tags names, generates the pango markup to render
         that list with the tag colors used in GTG

        @param tag_names: the list of the tags (strings)
        @return str: the pango markup string
        """
        if ALLTASKS_TAG in tag_names:
            tags_txt = ""
        else:
            tags_txt = get_colored_tags_markup(self.req, tag_names)
        return "<small>" + tags_txt + "</small>"