langchain: import InMemoryChatMessageHistory from core (#21198)

libs/langchain/langchain/memory/chat_message_histories/in_memory.py

@@ -1,21 +1,5 @@
-from typing import TYPE_CHECKING, Any
+from langchain_core.chat_history import InMemoryChatMessageHistory as ChatMessageHistory
 
-from langchain._api import create_importer
+__all__ = [
-
+    "ChatMessageHistory",
-if TYPE_CHECKING:
+]
-    from langchain_community.chat_message_histories.in_memory import ChatMessageHistory
-
-# Create a way to dynamically look up deprecated imports.
-# Used to consolidate logic for raising deprecation warnings and
-# handling optional imports.
-DEPRECATED_LOOKUP = {"ChatMessageHistory": "langchain_community.chat_message_histories"}
-
-_import_attribute = create_importer(__package__, deprecated_lookups=DEPRECATED_LOOKUP)
-
-
-def __getattr__(name: str) -> Any:
-    """Look up attributes dynamically."""
-    return _import_attribute(name)
-
-
-__all__ = ["ChatMessageHistory"]