How to use the pythoms.mass_abbreviations.abbrvs function in pythoms

"""
    Searches for abbreviations predefined in mass_abbreviations.py either in the pythoms package or in the current
    working directory. Any found abbreviations will be added to the current dictionary.

    :param dct: incoming dictionary
    :return: un-abbreviated dictionary
    :rtype: dict
    """
    comptemp = {}
    for key in dct:
        if key in abbrvs:  # if a common abbreviation is found in formula
            for subkey in abbrvs[key]:
                try:
                    comptemp[subkey] += abbrvs[key][subkey] * dct[key]
                except KeyError:
                    comptemp[subkey] = abbrvs[key][subkey] * dct[key]
        else:
            try:
                comptemp[key] += dct[key]
            except KeyError:
                comptemp[key] = dct[key]
    return comptemp