@Override
			public SetResponse lookupRecords(Name name, int type, int minCred) {
				final SetResponse setResponse = super.lookupRecords(name, type, minCred);
				if (count++ == 0) {
					assertThat(setResponse.isUnknown(), is(true));
				} else {
					assertThat(setResponse.isUnknown(), is(false));
				}
				return setResponse;    //To change body of overridden methods use File | Settings | File Templates.
			}
To test the custom DNS, should to add vm arguments as below:
-Dsun.net.spi.nameservice.provider.1=dns,LocalManagedDnsProxy
-Dngrinder.etc.hosts=10.0.0.1:www.google.com,10.0.0.2:www.google2.com.

@author JunHo Yoon
ngrinder-runtime/src/test/java/org/ngrinder/dns/LocalManagedDnsTest.java