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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 _is_always_unsatisfied(self):
 """Returns whether this requirement is always unsatisfied This would happen in cases where we can't determine the version from the filename. """

        # If this is a github sha tarball, then it is always unsatisfied
        # because the url has a commit sha in it and not the version
        # number.
        url = self._url()
        if url:
            filename = filename_from_url(url)
            if filename.endswith(ARCHIVE_EXTENSIONS):
                filename, ext = splitext(filename)
                if is_git_sha(filename):
                    return True
        return False