Address review comments

tests/test_stac_io.py

@@ -1,3 +1,4 @@
+import json
 import os
 import unittest
 import tempfile
@@ -103,14 +104,13 @@ class ReportingStacIO(DefaultStacIO, DuplicateKeyReportingMixin):
     def test_headers_stac_io(self, urlopen_mock: unittest.mock.MagicMock) -> None:
         stac_io = DefaultStacIO(headers={"Authorization": "api-key fake-api-key-value"})
 
-        try:
-            # note we don't care if this raises an exception, we just want to make
-            # sure urlopen was called with the appropriate headers
-            pystac.Catalog.from_file(
-                "https://example.com/catalog.json", stac_io=stac_io
-            )
-        except Exception:
-            pass
+        catalog = pystac.Catalog("an-id", "a description").to_dict()
+        # required until https://github.com/stac-utils/pystac/pull/896 is merged
+        catalog["links"] = []
+        urlopen_mock.return_value.__enter__.return_value.read.return_value = json.dumps(
+            catalog
+        ).encode("utf-8")
+        pystac.Catalog.from_file("https://example.com/catalog.json", stac_io=stac_io)
 
         request_obj = urlopen_mock.call_args[0][0]
         self.assertEqual(request_obj.headers, stac_io.headers)