@Nullable
	public Function<DnsNameResolverBuilder, DnsAddressResolverGroup> dnsAddressResolverGroupProvider() {
		return dnsAddressResolverGroupProvider;
	}
@Test
	void dnsAddressResolverGroupProvider() {
		assertThat(builder.build().dnsAddressResolverGroupProvider()).isNull();

		Function<DnsNameResolverBuilder, DnsAddressResolverGroup> provider = RoundRobinDnsAddressResolverGroup::new;
		builder.dnsAddressResolverGroupProvider(provider);
		assertThat(builder.build().dnsAddressResolverGroupProvider()).isEqualTo(provider);
	}