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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 get_performance_data(self, project, **params):
        '''
        Gets a dictionary of PerformanceSeries objects

        You can specify which signatures to get by passing signature to this function
        '''
        results = self._get_json(self.PERFORMANCE_DATA_ENDPOINT, project, **params)

        return {k: PerformanceSeries(v) for k, v in results.items()}