@Test
public void test_getExtensionLoader_NotInterface() throws Exception {

    try {
        getExtensionLoader(ExtensionLoaderTest.class);
        fail();
    } catch (IllegalArgumentException expected) {
        assertThat(expected.getMessage(),
                containsString("Extension type (class org.apache.dubbo.common.extension.ExtensionLoaderTest) is not an interface"));
    }
}