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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def quantity_to_hdf5(f, key, q):
 """ Turn an Astropy Quantity object into something we can write out to an HDF5 file. Parameters f : :class:`h5py.File`, :class:`h5py.Group`, :class:`h5py.DataSet` key : str The name. q : float, `astropy.units.Quantity` The quantity. """


    if hasattr(q, 'unit'):
        f[key] = q.value
        f[key].attrs['unit'] = str(q.unit)

    else:
        f[key] = q
        f[key].attrs['unit'] = ""