make sure the response is a handshake respone

src/main.rs

@@ -110,6 +110,7 @@ fn perform_handshake() -> Result<u128> {
 
     let end = Instant::now();
 
+    assert_eq!(buf[0], 2);
     assert_eq!(number_of_bytes, 92);
 
     Ok(end.duration_since(start).as_nanos())