public HealthCheckServiceBuilder checkers(HealthChecker... healthCheckers) {
        return checkers(ImmutableSet.copyOf(requireNonNull(healthCheckers, "healthCheckers")));
    }
Adds the specified {@link HealthChecker}s that determine the healthiness of the {@link Server}.

@return {@code this}
core/src/main/java/com/linecorp/armeria/server/healthcheck/HealthCheckServiceBuilder.java