code: public PdfDictionary getDeveloperExtensions() {
  		PdfDictionary developerextensions = new PdfDictionary();
  		developerextensions.put(PdfName.BASEVERSION, baseversion);
  		developerextensions.put(PdfName.EXTENSIONLEVEL, new PdfNumber(extensionLevel));
  		return developerextensions;
  	}
docs: Generations the developer extension dictionary corresponding
  with the prefix.
  @return	a PdfDictionary