How to use the pythoms.molecule.ReiterableCWR function in pythoms

:rtype: Spectrum
    """
    speciso = False  # set state for specific isotope
    isos = {}  # isotopes dictionary
    isosets = {}  # set of isotopes for each element
    iterators = []  # list of iterators
    nk = []
    for element in comp:  # for each element
        if element in mass_dict:
            isosets[element] = []  # set of isotopes
            for isotope in mass_dict[element]:  # for each isotope of that element in the mass dictionary
                if isotope != 0 and mass_dict[element][isotope][1] != 0:  # of the intensity is nonzero
                    isosets[element].append(isotope)  # track set of isotopes
                    isos[isotope] = element  # create isotope,element association for reference
            iterators.append(
                ReiterableCWR(  # create iterator instance
                    isosets[element],
                    comp[element]
                )
            )
            if verbose is True:
                nk.append([  # track n and k for list length output
                    len(isosets[element]),
                    comp[element]
                ])
        else:  # if it's an isotope
            speciso = True

    spec = Spectrum(  # initiate spectrum object
        decpl,  # decimal places
        start=None,  # no minimum mass
        end=None,  # no maximum mass