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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 read_json_breakdown(cls, fname):
 """Read json file to get fixture data"""

        if not os.path.exists(fname):
            raise RuntimeError

        with open(fname, 'r') as data_file:
            return cls.fixup_from_json(data_file.read())