def write_to(self, group, append=False):
        """Writes the properties to a `group`, or append it"""
        data = self.data
        if append is True:
            try:
                # concatenate original and new properties in a single list
                original = read_properties(group)
                data = original + data
            except EOFError:
                pass  # no former data to append on

        # h5py does not support embedded NULLs in strings ('\x00')
        data = pickle.dumps(data).replace(b'\x00', b'__NULL__')
        group['properties'][...] = np.void(data)
Writes the properties to a `group`, or append it