human
I wrote the below code

    def infinite_defaultdict():
        return collections.defaultdict(infinite_defaultdict)
    new_config = infinite_defaultdict()
    global verbose
    verbose = False
    valid_config = True
    valid_rule = True
    tool_has_default = False
    if return_bool:
        verbose = True
    elif ((obj is not None) and ('verbose' in obj) and isinstance(obj['verbose'], bool)):
        verbose = obj['verbose']
    else:
        valid_config = False
    if ((not return_bool) and verbose):
        log.debug('Running    config    validation...')
    if ((not valid_config) and return_bool):
        log.debug("Missing    mandatory    field    'verbose'    in    config!")
    available_rule_types = ['file_size', 'num_input_datasets', 'records', 'arguments']
    if (obj is not None):
        if ('default_destination' in obj):
            if isinstance(obj['default_destination'], str):
                new_config['default_destination'] = obj['default_destination']
            elif isinstance(obj['default_destination'], dict):
                if (('priority' in obj['default_destination']) and isinstance(obj['default_destination']['priority'], dict)):
                    if ('med' not in obj['default_destination']['priority']):
                        error = "No    default    'med'    priority    destination!"
                        if verbose:
                            log.debug(error)
                        valid_config = False
                    else:
                        for priority in obj['default_destination']['priority']:
                            if (priority in ['low', 'med', 'high']):
                                if isinstance(obj['default_destination']['priority'][priority], str):
                                    new_config['default_destination']['priority'][priority] = obj['default_destination']['priority'][priority]
                                else:
                                    error = (("No    default    '" + str(priority)) + "'    priority    destination    in    config!")
    ...

What's a good function header?
 Here's a good function header?
assistant
#Here's a good function header.

def validate_config(obj, return_bool=False):