protected final void invokeOnReady() {
        if (blockingExecutor != null && cancelled) {
            // Do not call listener.onReady() if the call is cancelled after
            // this task was scheduled to blockingTaskExecutor.
            return;
        }
        try {
            if (listener != null) {
                listener.onReady();
            }
        } catch (Throwable t) {
            close(t);
        }
    }
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