[PLT-1437] Restore client.headers (#1781)

Author: vbrodsky

libs/labelbox/src/labelbox/client.py

@@ -10,6 +10,7 @@
 from collections import defaultdict
 from datetime import datetime, timezone
 from typing import Any, List, Dict, Union, Optional, overload, Callable
+from types import MappingProxyType
 
 from labelbox.schema.search_filters import SearchFilter
 import requests
@@ -128,6 +129,10 @@ def _init_connection(self) -> requests.Session:
 
         return connection
 
+    @property
+    def headers(self) -> MappingProxyType:
+        return self._connection.headers
+
     def _default_headers(self):
         return {
             'Authorization': 'Bearer %s' % self.api_key,

libs/labelbox/tests/unit/test_client.py

@@ -0,0 +1,15 @@
+import os
+
+from unittest.mock import patch
+
+from labelbox.client import Client
+
+
+# @patch.dict(os.environ, {'LABELBOX_API_KEY': 'bar'})
+def test_headers():
+    client = Client(api_key="api_key", endpoint="http://localhost:8080/_gql")
+    assert client.headers
+    assert client.headers["Authorization"] == "Bearer api_key"
+    assert client.headers["Content-Type"] == "application/json"
+    assert client.headers["User-Agent"]
+    assert client.headers["X-Python-Version"]