private boolean isCurrentDataMultiPart() {
        // For now assume segmented and multi-part are mutually exclusive
        return lastResult != null
                && DataType.NON_SEGMENTED.equals(lastResult.getDataType());
    }
Compare the {@link DataRange}s using on the from/to {@link Location};
stroom-core-client/src/main/java/stroom/data/client/presenter/SourcePresenter.java