default boolean tryRequest() {
        return canRequest();
    }
Decides whether a request should be sent or failed depending on the current circuit state.
If the current state is {@link CircuitState#OPEN} and
{@link CircuitBreakerBuilder#circuitOpenWindow(Duration)} has passed, the state will enter
{@link CircuitState#HALF_OPEN}.
core/src/main/java/com/linecorp/armeria/client/circuitbreaker/CircuitBreaker.java