How to use the graphistry.pygraphistry.PyGraphistry.api_key function in graphistry

def _check_key_and_version():
        params = {'text': PyGraphistry.api_key()}
        try:
            response = requests.get(PyGraphistry._check_url(), params=params, timeout=(3,3),
                                    verify=PyGraphistry._config['certificate_validation'])
            response.raise_for_status()
            jres = response.json()

            cver = sys.modules['graphistry'].__version__
            if  'pygraphistry' in jres and 'minVersion' in jres['pygraphistry'] and 'latestVersion' in jres['pygraphistry']:
                mver = jres['pygraphistry']['minVersion']
                lver = jres['pygraphistry']['latestVersion']
                if util.compare_versions(mver, cver) > 0:
                    util.warn('Your version of PyGraphistry is no longer supported (installed=%s latest=%s). Please upgrade!' % (cver, lver))
                elif util.compare_versions(lver, cver) > 0:
                    print('A new version of PyGraphistry is available (installed=%s latest=%s).' % (cver, lver))

            if jres['success'] is not True:

**Example: Developer**
                ::

                    import graphistry
                    graphistry.register('my api key', server='staging', protocol='https')


        **Example: Through environment variable**
                ::
                    export GRAPHISTRY_API_KEY = 'my api key'
                ::
                    import graphistry
                    graphistry.register()
        """
        PyGraphistry.api_key(key)
        PyGraphistry.server(server)
        PyGraphistry.api_version(api)
        PyGraphistry.protocol(protocol)
        PyGraphistry.certificate_validation(certificate_validation)
        PyGraphistry.authenticate()
        PyGraphistry.set_bolt_driver(bolt)

def authenticate():
        """Authenticate via already provided configuration.
        This is called once automatically per session when uploading and rendering a visualization."""
        key = PyGraphistry.api_key()
        #Mocks may set to True, so bypass in that case
        if (key is None) and PyGraphistry._is_authenticated == False:
            util.error('API key not set explicitly in `register()` or available at ' + EnvVarNames['api_key'])
        if not PyGraphistry._is_authenticated:
            PyGraphistry._check_key_and_version()
            PyGraphistry._is_authenticated = True