How to use the graphistry.etl.Graphistry function in graphistry

Keywords arguments:
    server -- the Graphistry server. Possible values: "labs", "staging", "localhost" (default "labs")
    height -- the height of the plot in pixels (default 500)
    """

    if server is 'localhost':
        hostname = 'localhost:3000'
    elif server is 'staging':
        hostname = 'proxy-staging.graphistry.com'
    elif server is 'labs':
        hostname = 'proxy-labs.graphistry.com'
    else:
        hostname = server

    return Graphistry(hostname, height, url_params, key)