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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 describe_features(self, traj):
 """Return a list of dictionaries describing the atom pair features. Parameters traj : mdtraj.Trajectory The trajectory to describe Returns ------- feature_descs : list of dict Dictionary describing each feature with the following information about the atoms participating in each dihedral - resnames: unique names of residues - atominds: the two atom inds - resseqs: unique residue sequence ids (not necessarily 0-indexed) - resids: unique residue ids (0-indexed) - featurizer: AtomPairsFeaturizer - featuregroup: Distance. - other info : Value of the exponent """

        feature_descs = []

        top = traj.topology
        residue_indices = [[top.atom(i[0]).residue.index, top.atom(i[1]).residue.index] \
                           for i in self.atom_indices]

        aind = []
        resseqs = []
        resnames = []
        for ind,resid_ids in enumerate(residue_indices):
            aind += [[i for i in self.atom_indices[ind]]]
            resseqs += [[top.residue(ri).resSeq for ri in resid_ids]]
            resnames += [[top.residue(ri).name for ri in resid_ids]]

        zippy = itertools.product(["AtomPairs"], ["Distance"],
                                  ["Exponent {}".format(self.exponent)],
                                  zip(aind, resseqs, residue_indices, resnames))

        feature_descs.extend(dict_maker(zippy))
        return feature_descs