public static ClosedStreamException get() {
        return isSampled() ? new ClosedStreamException(null, null, true, true) : INSTANCE;
    }
Returns a {@link ClosedStreamException} which may be a singleton or a new instance, depending on
{@link Flags#verboseExceptionSampler()}'s decision.
core/src/main/java/com/linecorp/armeria/common/stream/ClosedStreamException.java