def METHOD_NAME(self, file_path: str) -> str:
    """Load the annotation of the NAF dataset.
    Args:
        file_path (str): Path to the json file
    Retyrb:
        str: Complete annotation of the json file
    """
    with open(file_path, 'r') as f:
        data = json.load(f)
    # 'textBBs' contains the printed texts of the table while 'fieldBBs'
    #  contains the text filled by human.
    for box_type in ['textBBs', 'fieldBBs']:
        if not self.det:
            # 'textBBs' is only used for detection task.
            if box_type == 'textBBs':
                continue
        for anno in data[box_type]:
            # Skip blanks
            if self.det:
                if box_type == 'fieldBBs':
                    if anno['type'] == 'blank':
                        continue
                poly = np.array(anno['poly_points']).reshape(
                    1, 8)[0].tolist()
                # Since detection task only need poly, we can skip the
                # transcription part that can be empty.
                text = None
            else:
                # For tasks that need transcription, NAF dataset has
                # serval special cases:
                # 1. The transcription for the whole image is not
                # available.
                # 2. The transcription for the certain text is not
                # available.
                # 3. If the length of the transcription is 0, it should
                # be ignored.
                if 'transcriptions' not in data.keys():
                    break
                if anno['id'] not in data['transcriptions'].keys():
                    continue
                text = data['transcriptions'][anno['id']]
                text = text.strip(
                    '\u202a')  # Remove unicode control character
                text = text.replace('»', '').replace(
                    '«', '')  # Remove strikethrough flag
                if len(text) == 0:
                    continue
                poly = np.array(anno['poly_points']).reshape(
                    1, 8)[0].tolist()
            yield poly, text