code: public ReactiveHealthIndicatorRegistry createReactiveHealthIndicatorRegistry(
  			Map<String, ReactiveHealthIndicator> reactiveHealthIndicators,
  			Map<String, HealthIndicator> healthIndicators) {
  		Assert.notNull(reactiveHealthIndicators,
  				"ReactiveHealthIndicators must not be null");
  		return initialize(new DefaultReactiveHealthIndicatorRegistry(),
  				reactiveHealthIndicators, healthIndicators);
  	}
docs: Create a {@link ReactiveHealthIndicatorRegistry} based on the specified health
  indicators. Each {@link HealthIndicator} are wrapped to a
  {@link HealthIndicatorReactiveAdapter}. If two instances share the same name, the
  reactive variant takes precedence.
  @param reactiveHealthIndicators the {@link ReactiveHealthIndicator} instances
  mapped by name
  @param healthIndicators the {@link HealthIndicator} instances mapped by name if
  any.
  @return a {@link ReactiveHealthIndicator} that delegates to the specified
  {@code reactiveHealthIndicators}.