docs/en/docs/tutorial/middleware.md: new section added: Class-Based Middleware

docs/en/docs/tutorial/middleware.md

@@ -65,6 +65,28 @@ Here we use <a href="https://docs.python.org/3/library/time.html#time.perf_count
 
 ///
 
+### Class-Based Middleware
+
+It is possible to define a custom `http` middleware using classes. 
+
+We will implement the class-based middleware with exactly the same functionality as in the example above.
+
+We will use an abstract `BaseHTTPMiddleware` class from Starlette that allows to write custom `http` middlewares.
+
+{* ../../docs_src/middleware/tutorial002.py hl[7:13,17] *}
+
+To create the middleware we need to override the `async dispatch` method of the `BaseHTTPMiddleware` class. 
+
+The functionality of the method is very similar to the decorated middleware function from the previous example.
+
+The middleware is connected to the FastAPI application using `app.add_middleware` method.
+
+/// note
+
+You can read more about Starlette middleware in [Starlette documentation](https://www.starlette.io/middleware).
+
+///
+
 ## Other middlewares
 
 You can later read more about other middlewares in the [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}.