Fix 403 (#222)

Author: tellet-q

Diff for: benchmark/dataset.py

@@ -4,6 +4,7 @@
 import urllib.request
 from dataclasses import dataclass, field
 from typing import Dict, Optional
+from urllib.request import build_opener, install_opener
 
 from benchmark import DATASETS_DIR
 from dataset_reader.ann_compound_reader import AnnCompoundReader
@@ -12,6 +13,12 @@
 from dataset_reader.json_reader import JSONReader
 from dataset_reader.sparse_reader import SparseReader
 
+# Needed for Cloudflare's firewall in ann-benchmarks
+# See https://github.com/erikbern/ann-benchmarks/pull/561
+opener = build_opener()
+opener.addheaders = [("User-agent", "Mozilla/5.0")]
+install_opener(opener)
+
 
 @dataclass
 class DatasetConfig: