def _load_file(self, path, filename):
        mtime = os.path.getmtime(filename)
        cached = self._file_cache.get(filename)

        if cached and cached[1] == mtime:
            page = cached[0]
        else:
            encoding = self.config('encoding')

            if compat.IS_PY3:
                with open(filename, encoding=encoding) as handler:
                    content = handler.read()
            else:
                with open(filename) as handler:
                    content = handler.read().decode(encoding)

            page = self._parse(content, path)
            self._file_cache[filename] = (page, mtime)

        return page
Load file from file system and put it to cached dict as :class:`Path`
dataset/ETHPy150Open SimonSapin/Flask-FlatPages/flask_flatpages/flatpages.py/FlatPages._load_file