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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 upgrade_api(request, client, version):
 """Ugrade the nova API to the specified version if possible."""


    min_ver, max_ver = api_versions._get_server_version_range(client)
    if min_ver <= api_versions.APIVersion(version) <= max_ver:
        client = _nova.novaclient(request, version)
    return client