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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 list_api_keys(awsclient):
 """Print the defined API keys. """

    _sleep()
    client_api = awsclient.get_client('apigateway')
    print('listing api keys')

    response = client_api.get_api_keys()['items']

    for item in response:
        print(json2table(item))