### Question:
GraphqlClientDataSourceServlet extends SlingSafeMethodsServlet { void unbindGraphqlClient(GraphqlClient graphqlClient, Map<?, ?> properties) { identifiers.remove(graphqlClient.getIdentifier()); }   final static String RESOURCE_TYPE; }### Answer:
@Test public void testUnbindGraphqlClient() { GraphqlClient mockClient = mock(GraphqlClient.class); Mockito.doReturn("my-identifier").when(mockClient).getIdentifier(); Set<String> identifiers = new HashSet<>(Arrays.asList("my-identifier", "another-identifier")); Whitebox.setInternalState(servlet, "identifiers", identifiers); servlet.unbindGraphqlClient(mockClient, Collections.emptyMap()); Assert.assertEquals(1, identifiers.size()); Assert.assertTrue(identifiers.contains("another-identifier")); }