chore: checkpoint before Python removal

vendor/futures/tests/future_inspect.rs

@@ -0,0 +1,16 @@
+use futures::executor::block_on;
+use futures::future::{self, FutureExt};
+
+#[test]
+fn smoke() {
+    let mut counter = 0;
+
+    {
+        let work = future::ready::<i32>(40).inspect(|val| {
+            counter += *val;
+        });
+        assert_eq!(block_on(work), 40);
+    }
+
+    assert_eq!(counter, 40);
+}