}
if (this.filtersLocked) {
throw new PdfException("Cannot add filters to PDFStream after "
+ "content has been written to the stream.");
}
PsFilterType psFilterType = null;
if (filterType.equals("flate")) {
psFilterType = PsFilterType.FLATE;
} else if (filterType.equals("ascii-85")) {
psFilterType = PsFilterType.ASCII_85;
} else if (filterType.equals("ascii-hex")) {