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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 extract_coverage(self, container: Container) -> FileLineSet: """ Extracts a report of the lines that have been executed since the last time that a coverage report was extracted. """

        uid = container.uid
        r = self.__api.post('containers/{}/read-coverage'.format(uid))
        if r.status_code == 200:
            return FileLineSet.from_dict(r.json())
        self.__api.handle_erroneous_response(r)