Change return value to _GroupedBarReturn

Author: timhoffm

lib/matplotlib/axes/_axes.py

@@ -3353,7 +3353,7 @@ def grouped_bar(self, heights, *, positions=None, group_spacing=1.5, bar_spacing
 
         # place the bars, but only use numerical positions, categorical tick labels
         # are handled separately below
-        result = []
+        bar_containers = []
         for i, (hs, label, color) in enumerate(
                 zip(heights, labels, colors)):
             lefts = (group_centers - 0.5 * group_distance + margin_abs
@@ -3364,15 +3364,15 @@ def grouped_bar(self, heights, *, positions=None, group_spacing=1.5, bar_spacing
             else:
                 bc = self.barh(lefts, hs, height=bar_width, align="edge",
                                label=label, color=color, **kwargs)
-            result.append(bc)
+            bar_containers.append(bc)
 
         if tick_labels is not None:
             if orientation == "vertical":
                 self.xaxis.set_ticks(group_centers, labels=tick_labels)
             else:
                 self.yaxis.set_ticks(group_centers, labels=tick_labels)
 
-        return result
+        return _GroupedBarReturn(bar_containers)
 
     @_preprocess_data()
     def stem(self, *args, linefmt=None, markerfmt=None, basefmt=None, bottom=0,