protected void importPicture(List<Picture> poiPictures, Sheet poiSheet, SSheet sheet) {
   for (Picture poiPicture : poiPictures) {
     PictureData poiPicData = poiPicture.getPictureData();
     Integer picDataIx = importedPictureData.get(poiPicData); // ZSS-735
     if (picDataIx != null) {
       sheet.addPicture(
           picDataIx.intValue(), toViewAnchor(poiSheet, poiPicture.getClientAnchor()));
     } else {
       Format format = Format.valueOfFileExtension(poiPicData.suggestFileExtension());
       if (format != null) {
         SPicture pic =
             sheet.addPicture(
                 format,
                 poiPicData.getData(),
                 toViewAnchor(poiSheet, poiPicture.getClientAnchor()));
         importedPictureData.put(poiPicData, pic.getPictureData().getIndex());
       } else {
         // TODO log we ignore a picture with unsupported format
       }
     }
   }
 }