AttributeError: 'str' object has no attribute 'item' with usage of xarray ODIM backend

[JS]

Hi, I am new to the library and I am using the xarray ODIM backend as shown in the documentation: https://docs.wradlib.org/en/stable/notebooks/fileio/wradlib_odim_backend.html?highlight=wrl.io.open_odim_dataset#Load-ODIM_H5-Volume-Data 

I am currently trying to load the ODIM-H5 Volume Data but I keep having the error:

AttributeError: 'str' object has no attribute 'item'

My traceback before the error is :

Traceback (most recent call last):

  File ~\untitled13.py:26 in <module>
    vol = wrl.io.open_odim_dataset(f)

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\hdf.py:85 in open_odim_dataset
    return open_radar_dataset(filename_or_obj, engine="odim", **kwargs)

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\xarray.py:1898 in open_radar_dataset
    ds = [

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\xarray.py:1899 in <listcomp>
    xr.open_dataset(filename_or_obj, group=grp, engine=engine, **kwargs)

  File ~\anaconda3\envs\wradlib\lib\site-packages\xarray\backends\api.py:495 in open_dataset
    backend_ds = backend.open_dataset(

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:511 in open_dataset
    ds = store_entrypoint.open_dataset(

  File ~\anaconda3\envs\wradlib\lib\site-packages\xarray\backends\store.py:24 in open_dataset
    vars, attrs = store.load()

  File ~\anaconda3\envs\wradlib\lib\site-packages\xarray\backends\common.py:123 in load
    (_decode_variable_name(k), v) for k, v in self.get_variables().items()

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:454 in get_variables
    [

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:457 in <listcomp>
    for k, v in substore.get_variables().items()

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:339 in get_variables
    [

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:340 in <listcomp>
    self.open_store_variable(k, v)

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\backends.py:327 in open_store_variable
    name, attrs = _get_odim_variable_name_and_attrs(name, self.root.what)

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\xarray.py:1169 in what
    return self._get_dset_what()

  File ~\anaconda3\envs\wradlib\lib\site-packages\wradlib\io\xarray.py:1315 in _get_dset_what
    attrs["quantity"] = what["quantity"].item().decode()

I am unable to obtain the variable 'vol'. I have copied pasted the code until [2]. Has anyone had this problem before and if so, how did you solve it?

Thanks in advance and best regards,

Jing