[uss_qualifier] add utility properties to QueryError

monitoring/monitorlib/fetch/__init__.py

@@ -459,6 +459,19 @@ def __init__(self, msg: str, queries: Optional[Union[Query, List[Query]]] = None
         else:
             self.queries = queries
 
+    @property
+    def last_status_code(self) -> int:
+        """Returns the status code of the last query present in this QueryError,
+        or 999 if this error contains no queries."""
+        if len(self.queries) == 0:
+            return 999
+        return self.queries[-1].status_code
+
+    @property
+    def query_timestamps(self) -> List[datetime.datetime]:
+        """Returns the timestamps of all queries present in this QueryError."""
+        return [q.request.timestamp for q in self.queries]
+
     @property
     def stacktrace(self) -> str:
         return stacktrace_string(self)