human
Solve the following python programming problem given the following code:
def annotool(args) : 
    '
    Perform operations on the annotation database.

    This command provides a way of running named commands across the database
    of annotations and can be used to run data migrations, analytics, etc.

    **NB**: This tool cannot currently be used for making changes to the
    annotation "document" field.
    ' 
    request = bootstrap (args) 
    annotations = es_helpers.scan (request.legacy_es.conn, query = { 
        'query' : { 
            'match_all' : { 
                
}, 
}, 
}, index = request.legacy_es.index, doc_type = request.legacy_es.t.annotation) 
    chunksize = 1000 
    state = { 
        'total' : 0, 
        'pending' : [], 
} 
    def _flush() : 
        bodies = [{ 
            '_index' : request.legacy_es.index, 
            '_type' : request.legacy_es.t.annotation, 
            '_op_type' : 'update', 
            '_id' : x ['_id'], 
            'doc' : x ['_source'], 
} for x in state ['pending']] 
        es_helpers.bulk (request.legacy_es.conn, bodies) 
        state ['total'] += len (state ['pending']) 
        log.info ('processed %d annotations', state ['total']) 
        state ['pending'] = [] 
for annotation in annotations : 
        func = ANNOTOOL_OPERATIONS [args.operation].load () 
        func (annotation ['_source']) 
        state ['pending'].append (_flush) 
        if (len (state ['pending']) >= chunksize) : 
            _flush () 
if state ['pending'] : 
        _flush () 

    
    

    Fix the buggy line: state ['pending'].append (_flush)
assistant
#Here is Python code to fix the buggy line: state ['pending'].

state ['pending'].append (annotation)