### Question:
SqsReceiverUtils { public static String region(Configuration conf) { return checkNotNull(stringProperty(conf, REGION), "Property " + REGION + " is not set"); } private  SqsReceiverUtils(); static String queue(Configuration conf); static String region(Configuration conf); static int waitTimeSeconds(Configuration conf); static AWSCredentialsProvider credentials(final Configuration conf);  }### Answer:
@Test public void regionIsNotNull() { conf.set(REGION.key(), "region"); assertThat(region(conf)).isEqualTo("region"); }
@Test(expected = IllegalArgumentException.class) public void regionIsNull() { conf.set(REGION.key(), null); region(conf); }