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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 find_first_version(self):
 """Finds the first version of igraph that exists in the nightly build repo from the version numbers provided in ``self.versions_to_try``."""

        for version in self.versions_to_try:
            remote_url = self.get_download_url(version=version)
            if http_url_exists(remote_url):
                return version, remote_url
        return None, None