How to use the taguette.extract.extract function in taguette

def test_extract_highlight(self):
        """Tests extracting a highlight from an HTML document."""
        html = '<p><u>H\xE9llo</u> R\xE9mi <i>what is</i> up ?</p>'
        snippet = extract.extract(html, 7, 15)
        self.assertEqual(snippet,
                         '<p>R\xE9mi <i>wh</i></p>')
        snippet = extract.extract(html, 1, 5)
        self.assertEqual(snippet,
                         '<p><u>\xE9ll</u></p>')
        snippet = extract.extract(html, 7, 12)
        self.assertEqual(snippet,
                         '<p>R\xE9mi</p>')

def test_extract_highlight(self):
        """Tests extracting a highlight from an HTML document."""
        html = '<p><u>H\xE9llo</u> R\xE9mi <i>what is</i> up ?</p>'
        snippet = extract.extract(html, 7, 15)
        self.assertEqual(snippet,
                         '<p>R\xE9mi <i>wh</i></p>')
        snippet = extract.extract(html, 1, 5)
        self.assertEqual(snippet,
                         '<p><u>\xE9ll</u></p>')
        snippet = extract.extract(html, 7, 12)
        self.assertEqual(snippet,
                         '<p>R\xE9mi</p>')

def test_extract_highlight(self):
        """Tests extracting a highlight from an HTML document."""
        html = '<p><u>H\xE9llo</u> R\xE9mi <i>what is</i> up ?</p>'
        snippet = extract.extract(html, 7, 15)
        self.assertEqual(snippet,
                         '<p>R\xE9mi <i>wh</i></p>')
        snippet = extract.extract(html, 1, 5)
        self.assertEqual(snippet,
                         '<p><u>\xE9ll</u></p>')
        snippet = extract.extract(html, 7, 12)
        self.assertEqual(snippet,
                         '<p>R\xE9mi</p>')

def post(self, project_id, document_id):
        obj = self.get_json()
        document = self.get_document(project_id, document_id, True)
        start, end = obj['start_offset'], obj['end_offset']
        snippet = extract.extract(document.contents, start, end)
        hl = database.Highlight(document=document,
                                start_offset=start,
                                end_offset=end,
                                snippet=snippet)
        self.db.add(hl)
        self.db.flush()  # Need to flush to get hl.id
        self.db.bulk_insert_mappings(database.HighlightTag, [
            dict(
                highlight_id=hl.id,
                tag_id=tag,
            )
            for tag in obj.get('tags', [])
        ])
        cmd = database.Command.highlight_add(
            self.current_user,
            document,

def post(self, project_id, document_id):
        document, privileges = self.get_document(project_id, document_id, True)
        if not privileges.can_add_highlight():
            self.set_status(403)
            return self.send_json({'error': "Unauthorized"})
        obj = self.get_json()
        start, end = obj['start_offset'], obj['end_offset']
        snippet = extract.extract(document.contents, start, end)
        hl = database.Highlight(document=document,
                                start_offset=start,
                                end_offset=end,
                                snippet=snippet)
        self.db.add(hl)
        self.db.flush()  # Need to flush to get hl.id
        new_tags = sorted(set(obj.get('tags', [])))
        self.db.bulk_insert_mappings(database.HighlightTag, [
            dict(
                highlight_id=hl.id,
                tag_id=tag,
            )
            for tag in new_tags
        ])
        cmd = database.Command.highlight_add(
            self.current_user,