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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 analyze_structures(self, structures, step_freq=10, most_frequent_polyhedra=15):
 """ Perform Voronoi analysis on a list of Structures. Note that this might take a significant amount of time depending on the size and number of structures. Args: structures (list):
 list of Structures cutoff (float: cutoff distance around an atom to search for neighbors step_freq (int):
 perform analysis every step_freq steps qhull_options (str):
 options to pass to qhull most_frequent_polyhedra (int):
 this many unique polyhedra with highest frequences is stored. Returns: A list of tuples in the form (voronoi_index,frequency) """

        voro_dict = {}
        step = 0
        for structure in structures:
            step += 1
            if step % step_freq != 0:
                continue

            v = []
            for n in range(len(structure)):
                v.append(str(self.analyze(structure, n=n).view()))
            for voro in v:
                if voro in voro_dict:
                    voro_dict[voro] += 1
                else:
                    voro_dict[voro] = 1
        return sorted(voro_dict.items(),
                      key=lambda x: (x[1], x[0]),
                      reverse=True)[:most_frequent_polyhedra]