diff --git a/mmif/serialize/mmif.py b/mmif/serialize/mmif.py
index e8957682..004be991 100644
--- a/mmif/serialize/mmif.py
+++ b/mmif/serialize/mmif.py
@@ -868,7 +868,4 @@ def __getitem__(self, item: str) -> Union[Document, View, Annotation, MmifMetada
                 ret = self.views._items.get(item)
                 if ret is None:
                     raise KeyError(f"Object with ID {item} not found in the MMIF object. ")
-                else:
-                    return ret
-            else:
-                return ret
+            return ret
diff --git a/mmif/serialize/model.py b/mmif/serialize/model.py
index 3c5e6986..b052b0fb 100644
--- a/mmif/serialize/model.py
+++ b/mmif/serialize/model.py
@@ -337,14 +337,14 @@ def __contains__(self, key: str) -> bool:
         try:
             self.__getitem__(key)
             return True
-        except (TypeError, AttributeError, KeyError):
+        except (TypeError, KeyError):
             return False
 
     def __getitem__(self, key) -> Any:
         if key in self._named_attributes():
             value = self.__dict__[key]
         elif self._unnamed_attributes is None:
-            raise AttributeError(f"Additional properties are disallowed by {self.__class__}: {key}")
+            raise KeyError(f"Additional properties are disallowed by {self.__class__}: {key}")
         else: 
             value = self._unnamed_attributes[key]
         if key not in self._required_attributes and self.is_empty(value):
diff --git a/tests/mmif_examples.py b/tests/mmif_examples.py
index 7e860c0a..b19f9d9a 100644
--- a/tests/mmif_examples.py
+++ b/tests/mmif_examples.py
@@ -1,6 +1,7 @@
 import itertools
 import os
 import subprocess
+from pathlib import Path
 from string import Template
 from urllib import request
 
@@ -20,8 +21,11 @@ def _load_from_url_or_git(url):
     If LOCALMMIF env var is set, use git show to load from local repo.
     LOCALMMIF should be the path to the local mmif repository.
     """
-    localmmif = os.environ.get('LOCALMMIF')
-    if localmmif:
+    localmmif_str = os.environ.get('LOCALMMIF')
+    if localmmif_str:
+        localmmif = Path(localmmif_str)
+        if not localmmif.is_dir():
+            raise ValueError(f"LOCALMMIF path is not a valid directory: {localmmif}")
         # Extract the version/branch and file path from the URL
         # URL format: https://raw.githubusercontent.com/clamsproject/mmif/{version}/{filepath}
         url_prefix = "https://raw.githubusercontent.com/clamsproject/mmif/"
@@ -35,7 +39,7 @@ def _load_from_url_or_git(url):
                 try:
                     result = subprocess.run(
                         ['git', 'show', git_ref],
-                        cwd=localmmif,
+                        cwd=str(localmmif),
                         capture_output=True,
                         text=True,
                         check=True