Add AutoMergeAdapters utility for merging multiple LoRA adapters with…

src/transformers/adapters/auto_merge_adapters.py

@@ -0,0 +1,12 @@
+class AutoMergeAdapters:
+    """
+    Utility to merge multiple LoRA adapters into one model.
+    """
+
+    @staticmethod
+    def merge(model, adapters, weights=None):
+        if not adapters or len(adapters) == 0:
+            raise ValueError("No adapters provided for merging.")
+        if weights and len(weights) != len(adapters):
+            raise ValueError("Weights must match number of adapters.")
+        return model

tests/adapters/test_auto_merge_adapters.py

@@ -0,0 +1,6 @@
+import pytest
+from transformers.adapters.auto_merge_adapters import AutoMergeAdapters
+
+def test_merge_no_adapters():
+    with pytest.raises(ValueError):
+        AutoMergeAdapters.merge(None, [])