@Test
public void removeExistingRoot() throws PatchApplicationException {

  store.put(DOCUMENT_ID, jsonNode1);
  PatchSet patchSet = patchSet(REMOVE, "", null);
  JsonNode result = underTest.processPatch(patchSet);
  assertThat(result, is(MissingNode.getInstance()));
  assertThat(store.get(DOCUMENT_ID), is(nullValue()));
}