private void addSeparator(boolean bolding, boolean dynteaser, FieldPart f, String toQuote,
                              List<FieldPart> newFieldParts, int previous, int j) {
        if (previous != j)
            newFieldParts.add(new StringFieldPart(toQuote.substring(previous, j), f.isToken()));
        if (dynteaser)
            newFieldParts.add(bolding ? new SeparatorFieldPart(separatorTag) : new SeparatorFieldPart(ELLIPSIS));
    }
This converts the backend binary highlighting of each item in an array of string field,
and creates a new field that replaces the original.
container-search/src/main/java/com/yahoo/prelude/searcher/JuniperSearcher.java