diff --git a/test/fixtures/server.py b/test/fixtures/server.py
index 959cdf6..6c94fc2 100644
--- a/test/fixtures/server.py
+++ b/test/fixtures/server.py
@@ -95,18 +95,19 @@ def core_operation(item_type, one_to_many, analysis_task):
             # yield page.get_pixmap().tobytes("png"), metadata
             yield f"page_{i}".encode()
 
+    params2op = {
+        False: {
+            "string": {False: upper},
+            "image": {False: rotate, True: classify},
+        },
+        True: {
+            "string": {False: duplicate},
+            "pdf": {False: stream_pages},
+        },
+    }
+
     try:
-        d = {
-            False: {
-                "string": {False: upper},
-                "image": {False: rotate, True: classify},
-            },
-            True: {
-                "string": {False: duplicate},
-                "pdf": {False: stream_pages},
-            },
-        }
-        return d[one_to_many][item_type][analysis_task]
+        return params2op[one_to_many][item_type][analysis_task]
     except KeyError:
         pytest.skip(f"No operation defined for parameter combination.")
         logger.debug(f"No operation defined for [{one_to_many=}, {item_type=}, {analysis_task=}].")