### Question:
AwsResource { public String getRegion() { return region; } AwsResource(String arn); String getArn(); String getResource(); String getService(); String getRegion(); @Override boolean equals(Object o); @Override int hashCode();  }### Answer:
@Test public void getRegion_GivenFirehoseArn_ShouldReturnUsEast1Region() { Assert.assertEquals("us-east-1", new AwsResource(firehoseArn).getRegion()); }
@Test public void getRegion_GivenS3Arn_ShouldReturnNullRegion() { Assert.assertNull(new AwsResource(s3Arn).getRegion()); }