diff --git a/api/responder.py b/api/responder.py
index 79431d5..7ad74fa 100644
--- a/api/responder.py
+++ b/api/responder.py
@@ -28,6 +28,10 @@ background_tasks: Set[asyncio.Task[Any]] = set()
 
 
 def create_background_task(coro: Coroutine[Any, Any, Any]) -> None:
+    """asyncio.create_task, which prevents the task from being garbage collected.
+
+    https://docs.python.org/3/library/asyncio-task.html#asyncio.create_task
+    """
     task = asyncio.create_task(coro)
     background_tasks.add(task)
     task.add_done_callback(background_tasks.discard)