def add_to_space_size(self, addition_bytes):
        # type: (int) -> None
        '''
        A method to add bytes to the space size tracked by this Volume
        Descriptor.

        Parameters:
         addition_bytes - The number of bytes to add to the space size.
        Returns:
         Nothing.
        '''
        if not self._initialized:
            raise pycdlibexception.PyCdlibInternalError('This Volume Descriptor is not yet initialized')
        # The 'addition' parameter is expected to be in bytes, but the space
        # size we track is in extents.  Round up to the next extent.
        self.space_size += utils.ceiling_div(addition_bytes, self.log_block_size)