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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 _generate_cache(self):
 """ Scan the path for distributions and populate the cache with those that are found. """

        gen_dist = not self._cache.generated
        gen_egg = self._include_egg and not self._cache_egg.generated
        if gen_dist or gen_egg:
            for dist in self._yield_distributions():
                if isinstance(dist, InstalledDistribution):
                    self._cache.add(dist)
                else:
                    self._cache_egg.add(dist)

            if gen_dist:
                self._cache.generated = True
            if gen_egg:
                self._cache_egg.generated = True