StagingDatabase mockIndexDb = mock(StagingDatabase.class);
Context mockCommands = mock(Context.class);
RefParse mockRefParse = mock(RefParse.class);
when(mockRefParse.setName(anyString())).thenReturn(mockRefParse);
when(mockCommands.command(eq(RefParse.class))).thenReturn(mockRefParse);
Optional<Ref> ref = Optional.absent();
when(mockRefParse.call()).thenReturn(ref);
List<ObjectId> oIds = Arrays.asList(ObjectId.forString("Object 1"),
ObjectId.forString("Object 2"));