methodDescriptor = locationResourceModel.findMethod(ResourceMethod.PARTIAL_UPDATE);
locationResource = getMockResource(AsyncLocationResource.class);
p = new PatchTree();
p.addOperation(new PathSpec("foo"), PatchOpFactory.setFieldOp(Integer.valueOf(51)));
PatchRequest<Location> expectedLocation = PatchRequest.createFromPatchDocument(p.getDataMap());
locationResource.update(eq(expectedLocation), EasyMock.<Callback<UpdateResponse>> anyObject());
EasyMock.expectLastCall().andAnswer(new IAnswer<Object>() {
@Override
public Object answer() throws Throwable {
@SuppressWarnings("unchecked")
Callback<UpdateResponse> callback = (Callback<UpdateResponse>) EasyMock.getCurrentArguments()[1];