add Sync trait to middleware error
@@ -144,7 +144,7 @@ pub trait FromErr<T> {
#[async_trait]
pub trait Middleware: Sync + Send + Debug {
- type Error: Send + Error + FromErr<<Self::Inner as Middleware>::Error>;
+ type Error: Sync + Send + Error + FromErr<<Self::Inner as Middleware>::Error>;
type Provider: JsonRpcClient;
type Inner: Middleware<Provider = Self::Provider>;
