def read(self, filename):
        '''
        Read a file content.

        :param string filename: The storage root-relative filename
        :raises FileNotFound: If the file does not exists
        '''
        if not self.backend.exists(filename):
            raise FileNotFound(filename)
        return self.backend.read(filename)
Read a file content.

        :param string filename: The storage root-relative filename
        :raises FileNotFound: If the file does not exists