public static Sampler<Class<? extends Throwable>> verboseExceptionSampler() {
        return VERBOSE_EXCEPTION_SAMPLER;
    }
Returns the specification of the {@link Sampler} that determines whether to retain the stack
trace of the exceptions that are thrown frequently by Armeria. A sampled exception will have the stack
trace while the others will have an empty stack trace to eliminate the cost of capturing the stack
trace.

<p>The default value of this flag is {@value DefaultFlagsProvider#VERBOSE_EXCEPTION_SAMPLER_SPEC},
which retains the stack trace of the exceptions at the maximum rate of 10 exceptions/sec.
Specify the {@code -Dcom.linecorp.armeria.verboseExceptions=<specification>} JVM option to override
the default. See {@link Sampler#of(String)} for the specification string format.</p>
core/src/main/java/com/linecorp/armeria/common/Flags.java