code: def write_hdf5_dict(tsdict, h5f, group=None, **kwargs):
      
      # create group if needed
      if group and group not in h5f:
          h5g = h5f.create_group(group)
      elif group:
          h5g = h5f[group]
      else:
          h5g = h5f
  
      # write each timeseries
      kwargs.setdefault('format', 'hdf5')
      for key, series in tsdict.items():
          series.write(h5g, path=str(key), **kwargs)
docs: Write a `TimeSeriesBaseDict` to HDF5
  
      Each series in the dict is written as a dataset in the group