add notebook 05 (colab) for test

tests/test_notebook_demos.py

@@ -1,5 +1,5 @@
 """
-This script test `demo_notebook_01en.ipynb` and `demo_notebook_01jp.ipynb` can run without error.
+This script test `demo_notebook_01en.ipynb`, `demo_notebook_01jp.ipynb`, and `demo_notebook_05en_for_google_colab.ipynb` can run without error.
 Implementation is awkward, but it works. Other jupyter notebook demos are not tested.
 """
 
@@ -51,3 +51,23 @@ def test_demo_notebook_01jp():
                     except Exception as e:
                         pytest.fail(f"Error in notebook {notebook}, cell:\n{cell.source}\n\nError: {str(e)}")
 
+def test_demo_notebook_05en():
+    notebook_dir = "demos_and_examples"
+    for notebook in os.listdir(notebook_dir):
+        if notebook.endswith(".ipynb") and "demo_notebook_05en_for_google_colab" in notebook :
+            full_path = os.path.join(notebook_dir, notebook)
+            with open(full_path, "r", encoding="utf-8") as f:
+                nb = nbformat.read(f, as_version=4)
+
+            for cell in nb.cells:
+                if cell.cell_type == "code":
+                    if "ResultGUIViewer" in cell.source or "%matplotlib" in cell.source or "!pip" in cell.source:
+                        print(f"Skipping cell in {notebook}: {cell.source[:50]}...")
+                        continue
+
+                    print("Testing:", cell.source[:50])
+                    try:
+                        exec(cell.source)
+                    except Exception as e:
+                        pytest.fail(f"Error in notebook {notebook}, cell:\n{cell.source}\n\nError: {str(e)}")
+