### Question:
NestedMetadata { static void putUriAttributes(Map<String, String> attributes, ObjectNode metadata) { putAttributes(attributes, metadata, Attribute.URI, ""); } private  NestedMetadata(); static byte[] mergedPayload(byte[] payload, byte[] metadata); static ObjectNode attributesToMetadataPayload(Map<String, String> attributes); static void stripPayloadMetadataToAttributes(Map<String, String> attributes,
      ObjectNode payload);  }### Answer:
@Test public void testPutUriAttributes() throws Exception { ObjectNode metadata = mapToObjectNode(ImmutableMap.of("uri", ImmutableMap .of("app_name", "Firefox", "app_update_channel", "release"))); Map<String, String> expected = ImmutableMap.of("app_name", "Firefox", "app_update_channel", "release"); Map<String, String> attributes = new HashMap<>(); NestedMetadata.putUriAttributes(attributes, (metadata)); assertEquals(expected, attributes); }