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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 iter_installable_versions(self):
 """Iterate through CPython versions available for Pipenv to install. """

        for name in self._pyenv('install', '--list').out.splitlines():
            try:
                version = Version.parse(name.strip())
            except ValueError:
                continue
            yield version