How to use the nmslib.freeIndex function in nmslib

nmslib.addDataPointBatch(index, np.arange(len(data), dtype=np.int32) + offset, data)
                offset += data.shape[0]
        print('offset', offset)
        nmslib.freeIndex(index)

    if seq:
        index = nmslib.init(
                             space_type,
                             space_param,
                             method_name,
                             nmslib.DataType.DENSE_VECTOR,
                             nmslib.DistType.FLOAT)
        with TimeIt('seq add data point'):
            for id, data in enumerate(read_data(f)):
                nmslib.addDataPoint(index, id, data)
        nmslib.freeIndex(index)

if not os.path.isfile(f):
        print('creating %s' % f)
        np.savetxt(f, np.random.rand(100000,1000), delimiter="\t")
        print('done')

    if fast:
        index = nmslib.init(
                             space_type,
                             space_param,
                             method_name,
                             nmslib.DataType.DENSE_VECTOR,
                             nmslib.DistType.FLOAT)
        with TimeIt('fast add data point'):
            data = read_data_fast(f)
            nmslib.addDataPointBatch(index, np.arange(len(data), dtype=np.int32), data)
        nmslib.freeIndex(index)

    if fast_batch:
        index = nmslib.init(
                             space_type,
                             space_param,
                             method_name,
                             nmslib.DataType.DENSE_VECTOR,
                             nmslib.DistType.FLOAT)
        with TimeIt('fast_batch add data point'):
            offset = 0
            for data in read_data_fast_batch(f, 10000):
                nmslib.addDataPointBatch(index, np.arange(len(data), dtype=np.int32) + offset, data)
                offset += data.shape[0]
        print('offset', offset)
        nmslib.freeIndex(index)

num_threads = 10
        query = read_data_fast('sample_queryset.txt')
        res = nmslib.knnQueryBatch(index, num_threads, k, query)
        for idx, v in enumerate(res):
            print(idx, v)
    else:
        for idx, data in enumerate(read_data('sample_queryset.txt')):
            print(idx, nmslib.knnQuery(index, k, data))
    end = time.time()
    print('querying done in %s secs' % (end - start))

    nmslib.saveIndex(index, index_name)

    print("The index %s is saved" % index_name)

    nmslib.freeIndex(index)

if idx < 5:
                    print(idx, v)
                if idx == 0:
                    for i in v:
                        print('q0', i, distance.cosine(q0, dataset[i,:]))
        else:
            for idx, data in enumerate(q):
                res = nmslib.knnQuery(index, k, data)
                if idx < 5:
                    print(idx, res)

    nmslib.saveIndex(index, index_name)

    print("The index %s is saved" % index_name)

    nmslib.freeIndex(index)

nmslib.loadIndex(index, index_name)

    print("The index %s is loaded" % index_name)

    nmslib.setQueryTimeParams(index, query_time_param)

    print('Query time parameters are set')

    print("Results for the loaded index:")

    k = 2
    for idx, data in enumerate(QUERY_STRS):
        print(idx, nmslib.knnQuery(index, k, data))

    nmslib.freeIndex(index)

print("Results for the freshly created index:")

    k = 2
    if batch:
        num_threads = 10
        res = nmslib.knnQueryBatch(index, num_threads, k, QUERY_STRS)
    for idx, data in enumerate(QUERY_STRS):
        res = nmslib.knnQuery(index, k, data)
        print(idx, data, res, [DATA_STRS[i] for i in res])

    nmslib.saveIndex(index, index_name)

    print("The index %s is saved" % index_name)

    nmslib.freeIndex(index)

nmslib.setQueryTimeParams(index,query_time_param)

    print('Query time parameters are set')

    print("Results for the freshly created index:")

    k = 3

    for idx, data in enumerate(read_sparse_data('sample_sparse_queryset.txt')):
        print(idx, nmslib.knnQuery(index, k, data))

    nmslib.saveIndex(index, index_name)

    print("The index %s is saved" % index_name)

    nmslib.freeIndex(index)

def freeIndex(self):
        nmslib.freeIndex(self._index)

def freeIndex(self):
        import nmslib
        nmslib.freeIndex(self._index)