error: use of deprecated method `DeprecatedClient::async_method`: please use `new_method` instead
  --> $DIR/rpc_deprecated_method.rs:63:20
   |
63 |     assert_eq!(client.async_method().await.unwrap(), 16);
   |                       ^^^^^^^^^^^^
   |
note: the lint level is defined here
  --> $DIR/rpc_deprecated_method.rs:4:9
   |
4  | #![deny(warnings)]
   |         ^^^^^^^^
   = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`