Returns a dictionary that associates the integer representation of each candidate with its
        position in the ranking, starting from 1.

def getRankMap(self):
        """
        Returns a dictionary that associates the integer representation of each candidate with its
        position in the ranking, starting from 1.
        """

        # We sort the candidates based on the number of incoming edges they have in the graph. If 
        # two candidates have the same number, we assume that they are tied.
        incEdgesMap = self.getIncEdgesMap()
        sortedKeys = sorted(incEdgesMap.keys(), reverse = True)
        rankMap = dict()
        pos = 1
        for key in sortedKeys:
            cands = incEdgesMap[key]
            for cand in cands:
                rankMap[cand] = pos
            pos += 1
        return rankMap