def get_indicator_source(self, sentinel_indicator_source):
        """To get the sentinel indicator source."""
        # To do: convert split function to startswith function for checking prefix.
        if (
            sentinel_indicator_source is not None
            and sentinel_indicator_source.split(":")[0].lower().strip()
            != COFENSE_SOURCE_PREFIX.split(":")[0].lower().strip()
        ):
            return sentinel_indicator_source
        else:
            return None
To get the sentinel indicator source.
Solutions/CofenseTriage/Data Connectors/CofenseTriageDataConnector/NonCofenseBasedIndicatorCreatorToCofense/sentinel_to_cofense_mapping.py