code: def write_to(self, group):
          
          # The HDF5 group where to write data
          items_group = group[self.name]
  
          nitems = items_group.shape[0]
          items_group.resize((nitems + len(self.data),))
          items_group[nitems:] = self.data
docs: Write stored items to the given HDF5 group.
  
          We assume that self.create() has been called.