boolean tryFinish() {
            return executionStateUpdater.compareAndSet(this,
                                                       ExecutionState.IDLE,
                                                       ExecutionState.FINISHED) ||
                   executionStateUpdater.compareAndSet(this,
                                                       ExecutionState.RUNNING,
                                                       ExecutionState.FINISHED);
        }
A {@link Factory} that creates a {@link Call} instance for {@link WebClient}.
retrofit2/src/main/java/com/linecorp/armeria/client/retrofit2/ArmeriaCallFactory.java