@Test
    public void testGetExtensionLoaderSPISubTypeNotMatchInterface() {
        try {
            ExtensionLoader.getExtensionLoader(NotMatchSPI.class).getJoin("subNoJoinSPI");
            fail();
        } catch (IllegalStateException expected) {
            assertThat(expected.getMessage(),
                    containsString("load extension resources error,class org.apache.shenyu.spi.fixture.SubNoJoinSPI subtype is not of interface org.apache.shenyu.spi.fixture.NotMatchSPI"));
        }
    }
test ExtensionLoader.getJoin() param name not interface subType case.
shenyu-spi/src/test/java/org/apache/shenyu/spi/ExtensionLoaderTest.java