Splunk Add-on Builder Custom Python Code: Issues setting initial checkpoint

[Blake_D]

Greetings,

I am writing a REST API call ingestion that requires authentication via first obtaining an auth token before the actual input, so I'm making use of the custom python code data ingestion builder for the first time.  Having issues with the initial setting of a checkpoint for the start date of the api call specifically.  I figure I need to check to see if the checkpoint exists, and if it doesn't - set the check point to the provided date from within the Data Input settings.  

When I try this with the below code snippet, I just get an error from the first line:

AttributeError: 'NoneType' object has no attribute 'encode'

ERROR 'NoneType' object has no attribute 'encode'

Not sure if there is a better way to set the initial check point somewhere that I'm not finding (this is in the collect_events function definition - so probably), or if there is a better way within python to handle the "if this doesn't exist, do this thing"

    start_date = helper.get_check_point(input_name)
    
    if start_date is None:
        helper.save_check_point(input_name, helper.get_arg("data_ingestion_start_date"))
        start_date = helper.get_check_point(input_name) 
        
    else:
        start_date = helper.get_check_point(input_name) 

[VatsalJagani]

Make sure the field `input_name` field is defined and it has the right string value.