How to use the xmlsec.shutdown function in xmlsec

print "Error: crypto initialization failed."
    
    # Init xmlsec-crypto library
    if xmlsec.cryptoInit() < 0:
        print "Error: xmlsec-crypto initialization failed."

    res = sign_file(sys.argv[1], sys.argv[2], sys.argv[3])

    # Shutdown xmlsec-crypto library
    xmlsec.cryptoShutdown()

    # Shutdown crypto library
    xmlsec.cryptoAppShutdown()

    # Shutdown xmlsec library
    xmlsec.shutdown()

    # Shutdown LibXML2
    libxml2.cleanupParser()

    sys.exit(res)

mngr = load_trusted_certs(sys.argv[2:], len(sys.argv) - 2)

    # Verify file
    if mngr is not None:
        res = verify_file(mngr, sys.argv[1])
        # Destroy keys manager
        mngr.destroy()
    
    # Shutdown xmlsec-crypto library
    xmlsec.cryptoShutdown()

    # Shutdown crypto library
    xmlsec.cryptoAppShutdown()

    # Shutdown xmlsec library
    xmlsec.shutdown()

    # Shutdown LibXML2
    libxml2.cleanupParser()

    sys.exit(res)

mngr = load_trusted_certs(sys.argv[2:], len(sys.argv) - 2)

    # Verify file
    if mngr is not None:
        res = verify_file(mngr, sys.argv[1])
        # Destroy keys manager
        mngr.destroy()
    
    # Shutdown xmlsec-crypto library
    xmlsec.cryptoShutdown()

    # Shutdown crypto library
    xmlsec.cryptoAppShutdown()

    # Shutdown xmlsec library
    xmlsec.shutdown()

    # Shutdown LibXML2
    libxml2.cleanupParser()

    sys.exit(res)

print "Error: crypto initialization failed."
    
    # Init xmlsec-crypto library
    if xmlsec.cryptoInit() < 0:
        print "Error: xmlsec-crypto initialization failed."

    res = encrypt_file(sys.argv[1], sys.argv[2], secret_data, len(secret_data))

    # Shutdown xmlsec-crypto library
    xmlsec.cryptoShutdown()

    # Shutdown crypto library
    xmlsec.cryptoAppShutdown()

    # Shutdown xmlsec library
    xmlsec.shutdown()

    # Shutdown LibXML2
    libxml2.cleanupParser()

    sys.exit(res)

print "Error: xmlsec-crypto initialization failed."

    # Create keys manager and load keys */
    mngr = create_files_keys_mngr()

    if mngr is not None:
        res = decrypt_file(mngr, sys.argv[1])

    # Shutdown xmlsec-crypto library
    xmlsec.cryptoShutdown()

    # Shutdown crypto library
    xmlsec.cryptoAppShutdown()

    # Shutdown xmlsec library
    xmlsec.shutdown()

    # Shutdown LibXML2
    libxml2.cleanupParser()

    sys.exit(res)

if key.setName(self.key_file) < 0:
        raise SignatureError('failed to set key name')

      # sign
      if dsigctx.sign(node) < 0:
        raise SignatureError('signing failed')
      signed_xml = doc.serialize()

    finally:
      if dsigctx:
        dsigctx.destroy()
      if doc:
        doc.freeDoc()
      xmlsec.cryptoShutdown()
      xmlsec.shutdown()
      libxml2.cleanupParser()

    return signed_xml