@Test
public void testSupports(){

	//测试凭据为空的情况。
	Assert.assertFalse(resolver.supports(null));
	
	//测试不支持的凭据类型的情况。
	Credential credential = Mockito.mock(Credential.class);
	Assert.assertFalse(resolver.supports(credential));
	
	//测试支持的凭据类型UsernamePasswordCredential的情况。
	credential = new UsernamePasswordCredential();
	Assert.assertTrue(resolver.supports(credential));
	
	
	//测试支持的凭据类型UsernamePasswordCredential的子类情况。
	credential = new SubUsernamePasswordCredential();
	Assert.assertTrue(resolver.supports(credential));
}