AIDA-82 Move test data to separate classes so that ExpectedPreviousResultsTest can use it.
AIDA-82 reuse SearchResultIterable.
AIDA-82 DummySearchResult allows a set of classifications.
AIDA-82 Create ExpectedPreviousResults class.
AIDA-82 Test whether Gson can write mocked objects: answer no, therefore test is ignored to avoid test errors.
AIDA-82 reading and writing in json format.
AIDA-82 Test write–read all results as expected.
AIDA-82 move json parsing into Builder.
AIDA-82 Walk the json parse tree.