add hints on asserts

csst_common/status.py

@@ -49,10 +49,14 @@ class CsstResult:
     ):
         if files is None:
             files = []
-        assert isinstance(status, CsstStatus)
-        assert isinstance(files, list)
+        assert isinstance(
+            status, CsstStatus
+        ), "`status` should be a `csst_common.CsstStatus` type objects."
+        assert isinstance(
+            files, list
+        ), "`files` should be a list of `str` type objects."
         for _ in files:
-            assert isinstance(_, str)
+            assert isinstance(_, str), "`files` should be a list of `str` type objects."
         self.status: CsstStatus = status
         self.files: Optional[list] = files
         self.output: dict = output