@Test
  public void testFallbackNoCreator() throws Exception {
    conf.setClass(HConstants.CLIENT_CONNECTION_REGISTRY_IMPL_CONF_KEY, RpcConnectionRegistry.class,
      ConnectionRegistry.class);
    ConnectionRegistryFactory.create(new URI("hbase+tls://server1:123/path"), conf, user);
    ArgumentCaptor<Class<?>> clazzCaptor = ArgumentCaptor.forClass(Class.class);
    ArgumentCaptor<Object[]> argsCaptor = ArgumentCaptor.forClass(Object[].class);
    mockedReflectionUtils
      .verify(() -> ReflectionUtils.newInstance(clazzCaptor.capture(), argsCaptor.capture()));
    assertEquals(RpcConnectionRegistry.class, clazzCaptor.getValue());
    assertSame(conf, argsCaptor.getValue()[0]);
    assertSame(user, argsCaptor.getValue()[1]);
  }
Make sure we can successfully parse the URI component
hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestConnectionRegistryUriParsing.java