class Media

    def absolute_path(self, path):
        """
        Given a relative or absolute path to a static asset, return an absolute
        path. An absolute path will be returned unchanged while a relative path
        will be passed to django.templatetags.static.static().
        """
        if path.startswith(('http://', 'https://', '/')):
            return path
        return static(path)

    @staticmethod
    def merge(list_1, list_2):
        """
        Merge two lists while trying to keep the relative order of the elements.
        Warn if the lists have the same two elements in a different relative
        order.

        For static assets it can be important to have them included in the DOM
        in a certain order. In JavaScript you may not be able to reference a
        global or in CSS you might want to override a style.
        """
        # Start with a copy of list_1.
        combined_list = list(list_1)
        last_insert_index = len(list_1)
        # Walk list_2 in reverse, inserting each element into combined_list if
        # it doesn't already exist.
        for path in reversed(list_2):
            try:
                # Does path already exist in the list?
                index = combined_list.index(path)
            except ValueError:
                # Add path to combined_list since it doesn't exist.
                combined_list.insert(last_insert_index, path)
            else:
                if index > last_insert_index:
                    warnings.warn(
                        'Detected duplicate Media files in an opposite order:\n'
                        '%s\n%s' % (combined_list[last_insert_index], combined_list[index]),
                        MediaOrderConflictWarning,
                    )
                # path already exists in the list. Update last_insert_index so
                # that the following elements are inserted in front of this one.
                last_insert_index = index
        return combined_list

    def render(self):
        return mark_safe('\n'.join(chain.from_iterable(getattr(self, 'render_' + name)() for name in MEDIA_TYPES)))

    def render_css(self):
        # To keep rendering order consistent, we can't just iterate over items().
        # We need to sort the keys, and iterate over the sorted list.
        media = sorted(self._css)
        return chain.from_iterable([
            format_html(
                '<link href="{}" type="text/css" media="{}" rel="stylesheet">',
                self.absolute_path(path), medium
            ) for path in self._css[medium]
        ] for medium in media)

    def render_js(self):
        return [
            format_html(
                '<script type="text/javascript" src="{}"></script>',
                self.absolute_path(path)
            ) for path in self._js
        ]