@Test
  public void serviceDocumentEmpty() throws Exception {
    Edm edm = mock(Edm.class);
    EdmServiceMetadata metadata = mock(EdmServiceMetadata.class);
    when(edm.getServiceMetadata()).thenReturn(metadata);
    final ODataResponse response =
        new JsonEntityProvider().writeServiceDocument(edm, "http://host:80/service/");
    assertNotNull(response);
    assertNotNull(response.getEntity());
    assertEquals(HttpContentType.APPLICATION_JSON, response.getContentHeader());
    assertEquals(ODataServiceVersion.V10, response.getHeader(ODataHttpHeaders.DATASERVICEVERSION));

    final String json = StringHelper.inputStreamToString((InputStream) response.getEntity());
    assertNotNull(json);
    assertEquals("{\"d\":{\"EntitySets\":[]}}", json);
  }
  @Test
  public void serviceDocument() throws Exception {
    Edm edm = mock(Edm.class);
    EdmServiceMetadata metadata = mock(EdmServiceMetadata.class);
    EdmEntitySetInfo entitySetInfo1 = mock(EdmEntitySetInfo.class);
    when(entitySetInfo1.getEntitySetUri()).thenReturn(URI.create("EntitySet"));
    EdmEntitySetInfo entitySetInfo2 = mock(EdmEntitySetInfo.class);
    when(entitySetInfo2.getEntitySetUri()).thenReturn(URI.create("Container2.EntitySet2"));
    when(metadata.getEntitySetInfos()).thenReturn(Arrays.asList(entitySetInfo1, entitySetInfo2));
    when(edm.getServiceMetadata()).thenReturn(metadata);
    final ODataResponse response =
        new JsonEntityProvider().writeServiceDocument(edm, "http://host:80/service/");
    assertNotNull(response);
    assertNotNull(response.getEntity());
    assertEquals(HttpContentType.APPLICATION_JSON, response.getContentHeader());
    assertEquals(ODataServiceVersion.V10, response.getHeader(ODataHttpHeaders.DATASERVICEVERSION));

    final String json = StringHelper.inputStreamToString((InputStream) response.getEntity());
    assertNotNull(json);
    assertEquals("{\"d\":{\"EntitySets\":[\"EntitySet\",\"Container2.EntitySet2\"]}}", json);
  }