code: def write_to(self, group, append=False):
          
          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)
docs: Writes the properties to a `group`, or append it