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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 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