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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 tally_role_columns(self):
 """ Sum up all of the stat columns. """

        totals = self.report["totals"]
        roles = self.report["roles"]

        totals["dependencies"] = sum(roles[item]
                                     ["total_dependencies"] for item in roles)
        totals["defaults"] = sum(roles[item]
                                 ["total_defaults"] for item in roles)
        totals["facts"] = sum(roles[item]["total_facts"] for item in roles)
        totals["files"] = sum(roles[item]["total_files"] for item in roles)
        totals["lines"] = sum(roles[item]["total_lines"] for item in roles)