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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 from_sites(cls, sites, charge=0, spin_multiplicity=None, validate_proximity=False):
 """ Convenience constructor to make a Molecule from a list of sites. Args: sites ([Site]):
 Sequence of Sites. charge (int):
 Charge of molecule. Defaults to 0. spin_multiplicity (int):
 Spin multicipity. Defaults to None, in which it is determined automatically. validate_proximity (bool):
 Whether to check that atoms are too close. """

        props = collections.defaultdict(list)
        for site in sites:
            for k, v in site.properties.items():
                props[k].append(v)
        return cls([site.species for site in sites],
                   [site.coords for site in sites],
                   charge=charge, spin_multiplicity=spin_multiplicity,
                   validate_proximity=validate_proximity,
                   site_properties=props)