@Deprecated
    public static String verboseExceptionSamplerSpec() {
        // XXX(trustin): Is it worth allowing to specify different specs for different exception types?
        return VERBOSE_EXCEPTION_SAMPLER_SPEC;
    }
Returns the specification string of the {@link Sampler} that determines whether to retain the
stack trace of the exceptions that are thrown frequently by Armeria.

@see #verboseExceptionSampler()
@deprecated Use {@link #verboseExceptionSampler()} and
            {@code -Dcom.linecorp.armeria.verboseExceptions=<specification>}.
core/src/main/java/com/linecorp/armeria/common/Flags.java