Fix for older python.

from: https://github.com/comfyanonymous/ComfyUI/discussions/476

comfy_extras/nodes_mask.py

@@ -187,12 +187,11 @@ class MaskComposite:
         source_portion = source[:visible_height, :visible_width]
         destination_portion = destination[top:bottom, left:right]
 
-        match operation:
-            case "multiply":
+        if operation == "multiply":
             output[top:bottom, left:right] = destination_portion * source_portion
-            case "add":
+        elif operation == "add":
             output[top:bottom, left:right] = destination_portion + source_portion
-            case "subtract":
+        elif operation == "subtract":
             output[top:bottom, left:right] = destination_portion - source_portion
 
         output = torch.clamp(output, 0.0, 1.0)