How to use the strax.load_file function in strax

def read(self, dirname: str, executor=None):
        """Iterates over strax results from directory dirname"""
        with open(dirname + '/metadata.json', mode='r') as f:
            metadata = json.loads(f.read())
        if not len(metadata['chunks']):
            self.log.warning(f"No data files in {dirname}?")
        dtype = literal_eval(metadata['dtype'])
        compressor = metadata['compressor']

        kwargs = dict(dtype=dtype, compressor=compressor)
        for chunk_info in metadata['chunks']:
            fn = os.path.join(dirname, chunk_info['filename'])
            if executor is None:
                yield strax.load_file(fn, **kwargs)
            else:
                yield executor.submit(strax.load_file, fn, **kwargs)

def _read_chunk(self, dirname, chunk_info, dtype, compressor):
        fn = osp.join(dirname, chunk_info['filename'])
        return strax.load_file(fn, dtype=dtype, compressor=compressor)

def _read_chunk(self, backend_key, chunk_info, dtype, compressor):
        # Temporary hack for backward compatibility
        if 'filename' in chunk_info:
            chunk_info['key_name'] = f"{backend_key}/{chunk_info['filename']}"

        with tempfile.SpooledTemporaryFile() as f:
            self.s3.download_fileobj(Bucket=BUCKET_NAME,
                                     Key=chunk_info['key_name'],
                                     Fileobj=f)
            f.seek(0)  # Needed?
            return strax.load_file(f,
                                   dtype=dtype,
                                   compressor=compressor)

def _read_chunk(self, zipn_and_dirn, chunk_info, dtype, compressor):
        zipn, dirn = zipn_and_dirn
        with zipfile.ZipFile(zipn) as zp:
            with zp.open(dirn + '/' + chunk_info['filename']) as f:
                return strax.load_file(f, dtype=dtype, compressor=compressor)

def _load_chunk(self, path, kind='central'):
        records = [strax.load_file(fn,
                                   compressor='blosc',
                                   dtype=strax.record_dtype())
                   for fn in glob.glob(f'{path}/reader_*')]
        records = np.concatenate(records)
        records = strax.sort_by_time(records)
        if kind == 'central':
            result = records
        else:
            result = strax.from_break(
                records,
                safe_break=self.config['safe_break_in_pulses'],
                left=kind == 'post',
                tolerant=True)
        if self.config['erase']:
            shutil.rmtree(path)
        return result