Add async methods to InMemoryCache (#17425)

Add async methods to InMemoryCache

libs/community/langchain_community/cache.py

@@ -192,6 +192,20 @@ class InMemoryCache(BaseCache):
         """Clear cache."""
         self._cache = {}
 
+    async def alookup(self, prompt: str, llm_string: str) -> Optional[RETURN_VAL_TYPE]:
+        """Look up based on prompt and llm_string."""
+        return self.lookup(prompt, llm_string)
+
+    async def aupdate(
+        self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE
+    ) -> None:
+        """Update cache based on prompt and llm_string."""
+        self.update(prompt, llm_string, return_val)
+
+    async def aclear(self, **kwargs: Any) -> None:
+        """Clear cache."""
+        self.clear()
+
 
 Base = declarative_base()