private void set(Property property, Date value) {
        if (value != null) {
            metadata.set(property, value);
        }
    }
Attempt to parse custom document properties and add to the collection of metadata

@param customProperties
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/SummaryExtractor.java