example to ensure structs are send

Cargo.toml

@@ -41,3 +41,4 @@ quickcheck = "0.8.5"
 data-encoding = "2.1.2"
 remove_dir_all = "0.5.2"
 tempfile = "3.1.0"
+async-std = "1.5.0"

examples/async.rs

@@ -0,0 +1,30 @@
+use async_std::task;
+use failure::Error;
+use hypercore::Feed;
+use random_access_storage::RandomAccess;
+use std::fmt::Debug;
+
+async fn append<T>(feed: &mut Feed<T>, content: &[u8])
+where
+    T: RandomAccess<Error = Error> + Debug,
+{
+    feed.append(content).unwrap();
+}
+
+async fn print<T>(feed: &mut Feed<T>)
+where
+    T: RandomAccess<Error = Error> + Debug,
+{
+    println!("{:?}", feed.get(0));
+    println!("{:?}", feed.get(1));
+}
+
+fn main() {
+    task::block_on(task::spawn(async {
+        let mut feed = Feed::default();
+
+        append(&mut feed, b"hello").await;
+        append(&mut feed, b"world").await;
+        print(&mut feed).await;
+    }));
+}