Returns a string representation of the tracker object for the given item.
    
    Args:
        item: object to get tracker for.
        fqdn (str): fully-qualified domain name of the object.

def _tracker_str(item):
    """Returns a string representation of the tracker object for the given item.
    
    Args:
        item: object to get tracker for.
        fqdn (str): fully-qualified domain name of the object.
    """
    instance = tracker(item)
    if instance is not None:
        if isinstance(instance, str):
            return instance
        elif isinstance(instance, tuple):
            return instance
        else:
            return instance.uuid
    else:
        #Must be a simple built-in type like `int` or `float`, in which case we
        #don't want to convert it to a string.
        return item