How to use the s3contents.genericfs.NoSuchFile function in s3contents

def __init__(self, path, *args, **kwargs):
        self.path = path
        self.message = "No such file or directory: {}".format(path)
        super(NoSuchFile, self).__init__(self.message, *args, **kwargs)

def read(self, path, format):
        path_ = self.path(path)
        if not self.isfile(path):
            raise NoSuchFile(path_)
        with self.fs.open(path_, mode="rb") as f:
            content = f.read().decode("utf-8")
        return content, "text"

def _file_model_from_path(self, path, content=False, format=None):
        """
        Build a file model from database record.
        """
        model = base_model(path)
        model["type"] = "file"
        if self.fs.isfile(path):
            model["last_modified"] = model["created"] = self.fs.lstat(path)["ST_MTIME"]
        else:
            model["last_modified"] = model["created"] = DUMMY_CREATED_DATE
        if content:
            try:
                # Get updated format from fs.read()
                content, format_ = self.fs.read(path, format)
            except NoSuchFile as e:
                self.no_such_entity(e.path)
            except GenericFSError as e:
                self.do_error(str(e), 500)
            model["format"] = format_
            model["content"] = content
            model["mimetype"] = mimetypes.guess_type(path)[0] or "text/plain"
        return model

def read(self, path, format):
        path_ = self.path(path)
        if not self.isfile(path):
            raise NoSuchFile(path_)
        with self.fs.open(path_, mode="rb") as f:
            content = f.read()
        if format is None or format == "text":
            # Try to interpret as unicode if format is unknown or if unicode
            # was explicitly requested.
            try:
                return content.decode("utf-8"), "text"
            except UnicodeError:
                if format == "text":
                    err = "{} is not UTF-8 encoded".format(path_)
                    self.log.error(err)
                    raise HTTPError(400, err, reason="bad format")
        return base64.b64encode(content).decode("ascii"), "base64"