return none if document or question is none

app.py

@@ -240,6 +240,8 @@ MODELS = {
 
 
 def process_question(question, document, model=list(MODELS.keys())[0]):
+    if not question or document is None:
+        return None, None, None
     prediction = MODELS[model](question=question, document=document)
     pages = [x.copy().convert("RGB") for x in document.preview]
     text_value = prediction["answer"]
@@ -403,32 +405,13 @@ examples = [
     [
         "bill_of_lading_1.png",
         "What is the shipper?",
-    ],
-    [
-        "bill_of_lading_1.png",
-        "What is the consignee?",
-    ],
-    [
-        "bill_of_lading_1.png",
-        "What is the consignee id?",
-    ],
-    [
-        "bill_of_lading_1.png",
-        "What is the carrier id?",
-    ],
-    [
-        "bill_of_lading_1.png",
-        "What is the description of the products?",
-    ],
-    [
-        "bill_of_lading_1.png",
-        "What is the quantity of the products?",
-    ],
+    ]
 ]
 
 with gr.Blocks(css=CSS) as demo:
-    gr.Markdown("# Document Query Engine")
-    gr.Markdown("### Compare performance of different document layout models. If you have any suggestions [contact me](https://www.linkedin.com/in/vincent-claes-0b346337/)")
+    gr.Markdown("# Document Query Engine</center>")
+    gr.Markdown("__Compare performance of different document layout models.__")
+    gr.Markdown("__If you have any suggestions [contact me](https://www.linkedin.com/in/vincent-claes-0b346337/)__")
 
     document = gr.Variable()
     example_question = gr.Textbox(visible=False)