Improved custom stamping visitor documentation (celery#7745)

docs/userguide/canvas.rst

@@ -1201,7 +1201,7 @@ pattern. The class that implements this custom logic must
 inherit ``VisitorStamping`` and implement appropriate methods.
 
 For example, the following example ``InGroupVisitor`` will label
-tasks that are in side of some group by lable ``in_group``.
+tasks that are in side of some group by label ``in_group``.
 
 .. code-block:: python
 
@@ -1221,3 +1221,33 @@ tasks that are in side of some group by lable ``in_group``.
 
         def on_signature(self, sig, **headers) -> dict:
             return {"in_group": [self.in_group], "stamped_headers": ["in_group"]}
+
+The following example shows another custom stamping visitor, which labels all
+tasks with a custom ``monitoring_id`` which can represent a UUID value of an external monitoring system,
+that can be used to track the task execution by including the id with such a visitor implementation.
+This ``monitoring_id`` can be a randomly generated UUID, or a unique identifier of the span id used by
+the external monitoring system.
+
+.. code-block:: python
+
+    class MonitoringIdStampingVisitor(StampingVisitor):
+        def on_signature(self, sig, **headers) -> dict:
+            return {'monitoring_id': uuid4(), 'stamped_headers': ['monitoring_id']}
+
+Next, lets see how to use the ``MonitoringIdStampingVisitor`` stamping visitor.
+
+.. code-block:: python
+
+    sig_example = signature('t1')
+    sig_example.stamp(visitor=MonitoringIdStampingVisitor())
+
+    group_example = group([signature('t1'), signature('t2')])
+    group_example.stamp(visitor=MonitoringIdStampingVisitor())
+
+    chord_example = chord([signature('t1'), signature('t2')], signature('t3'))
+    chord_example.stamp(visitor=MonitoringIdStampingVisitor())
+
+    chain_example = chain(signature('t1'), group(signature('t2'), signature('t3')), signature('t4'))
+    chain_example.stamp(visitor=MonitoringIdStampingVisitor())
+
+Lastly, it's important to mention that each monitoring id stamp in the example above would be different from each other between tasks.