Brought over flip flop prototype from contentis' fork, limiting it to only Qwen to ease the process of adapting it to be a native feature

comfy_extras/nodes_flipflop.py

@@ -0,0 +1,28 @@
+from comfy.ldm.flipflop_transformer import FLIPFLOP_REGISTRY
+
+class FlipFlop:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {"required":
+                    {"model": ("MODEL",), },
+                }
+
+    RETURN_TYPES = ("MODEL",)
+    FUNCTION = "patch"
+
+    OUTPUT_NODE = False
+
+    CATEGORY = "_for_testing"
+
+    def patch(self, model):
+        patch_cls = FLIPFLOP_REGISTRY.get(model.model.diffusion_model.__class__.__name__, None)
+        if patch_cls is None:
+            raise ValueError(f"Model {model.model.diffusion_model.__class__.__name__} not supported")
+
+        model.model.diffusion_model = patch_cls.patch(model.model.diffusion_model)
+
+        return (model,)
+
+NODE_CLASS_MAPPINGS = {
+    "FlipFlop": FlipFlop
+}