public final void setListener(Listener<I> listener) {
        checkState(this.listener == null, "listener already set");
        this.listener = requireNonNull(listener, "listener");
        invokeOnReady();
    }
Cancels a call when the call was closed by a client, not by server.
grpc/src/main/java/com/linecorp/armeria/internal/server/grpc/AbstractServerCall.java