/** Overriden to unconditionally allow the replace if ignoreDocumentMutate is true. */
 void replace(
     DocumentFilter.FilterBypass fb, int offset, int length, String text, AttributeSet attrs)
     throws BadLocationException {
   if (ignoreDocumentMutate) {
     fb.replace(offset, length, text, attrs);
     return;
   }
   super.replace(fb, offset, length, text, attrs);
 }