Add is_initialized() to base persister interface for compatibility

burr/core/application.py

@@ -2207,10 +2207,14 @@ def with_state_persister(
         """
         if on_every != "step":
             raise ValueError(f"on_every {on_every} not supported")
-        if hasattr(persister, 'initialize') and not persister.is_initialized():
-            raise RuntimeError(
-            "Uninitialized persister. Make sure to call .initialize() before passing it to the ApplicationBuilder."
-            )
+
+        # Check if 'is_initialized' exists and whether it returns False, indicating the persister is uninitialized
+        if hasattr(persister, 'is_initialized'):
+            if not persister.is_initialized():
+                raise RuntimeError(
+                    "RuntimeError: Uninitialized persister. Make sure to call .initialize() before passing it to the ApplicationBuilder"
+                )
+        # If the persister is valid and initialized, add it to lifecycle adapters
         if not isinstance(persister, persistence.BaseStateSaver):
             self.lifecycle_adapters.append(persister)
         else:

burr/core/persistence.py

@@ -88,7 +88,11 @@ class BaseStatePersister(BaseStateLoader, BaseStateSaver, metaclass=ABCMeta):
     Extend this class if you want an easy way to implement custom state storage.
     """
 
-    pass
+    def is_initialized(self) -> bool:
+        """Check if the persister has been initialized. Default behavior is False.
+        Persisters that require initialization can override this method.
+        """
+        return False
 
 
 class PersisterHook(PostRunStepHook):