protected void setUnknown_000c(int unknown_000c) {
        this.unknown_000c = unknown_000c;
    }
Sets 000c unknown bytes Unknown means here that those guys who cracked
the chm format do not know what's it purposes for

@param unknown_000c
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/chm/ChmItspHeader.java