private Picture nextUnclaimed() {
            Picture p = null;
            while (pn < nonU1based.size()) {
                p = nonU1based.get(pn);
                pn++;
                if (p != null) {
                    return p;
                }
            }
            return null;
        }
Return the next unclaimed one, used towards
the end
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/WordExtractor.java