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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 coverage(self, bug: Bug) -> TestSuiteCoverage: """ Provides coverage information for each test within the test suite for the program associated with this bug. Parameters: bug: the bug for which to compute coverage. Returns: a test suite coverage report for the given bug. """

        # determine the location of the coverage map on disk
        fn = os.path.join(self.__installation.coverage_path,
                          "{}.coverage.yml".format(bug.name))

        # is the coverage already cached? if so, load.
        if os.path.exists(fn):
            return TestSuiteCoverage.from_file(fn)

        # if we don't have coverage information, compute it
        mgr_ctr = self.__installation.containers
        container = None
        try:
            container = mgr_ctr.provision(bug)
            coverage = mgr_ctr.coverage(container)

            # save to disk
            with open(fn, 'w') as f:
                yaml.dump(coverage.to_dict(), f, default_flow_style=False)
        finally:
            if container:
                del mgr_ctr[container.id]

        return coverage