Add missing `Middleware` import on `BaseHTTPMiddleware` section (#1844)

diff --git a/docs/middleware.md b/docs/middleware.md
index 6b8ccf902f1bc005fd52c276c59b5a602ef9e402..5d6a32f3a8c3c1a4ec57e77363131ca90a570e23 100644 (file)
--- a/docs/middleware.md
+++ b/docs/middleware.md
@@ -190,8 +190,11 @@ To implement a middleware class using `BaseHTTPMiddleware`, you must override th
 `async def dispatch(request, call_next)` method.
 
 ```python
+from starlette.applications import Starlette
+from starlette.middleware import Middleware
 from starlette.middleware.base import BaseHTTPMiddleware
 
+
 class CustomHeaderMiddleware(BaseHTTPMiddleware):
     async def dispatch(self, request, call_next):
         response = await call_next(request)