From a87b88a488dc35bd2190d7216c541c837ce34552 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Sat, 8 Apr 2023 15:37:16 +0200
Subject: [PATCH] Fix CellInstanceFilter docstring

---
 openmc/filter.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/openmc/filter.py b/openmc/filter.py
index cc7bdd931..5233908c8 100644
--- a/openmc/filter.py
+++ b/openmc/filter.py
@@ -4,6 +4,7 @@ from collections.abc import Iterable
 import hashlib
 from itertools import product
 from numbers import Real, Integral
+import warnings
 from xml.etree import ElementTree as ET
 
 import numpy as np
@@ -588,7 +589,7 @@ class CellInstanceFilter(Filter):
     bins : iterable of 2-tuples or numpy.ndarray
         The cell instances to tally, given as 2-tuples. For the first value in
         the tuple, either openmc.Cell objects or their integral ID numbers can
-        be used.
+        be used. The second value indicates the cell instance.
     filter_id : int
         Unique identifier for the filter