private void initGuardedBlocks(Place shreds) {
   int origOffset = -1;
   int curOffset = 0;
   for (PsiLanguageInjectionHost.Shred shred : shreds) {
     Segment hostRangeMarker = shred.getHostRangeMarker();
     int start = shred.getRange().getStartOffset() + shred.getPrefix().length();
     int end = shred.getRange().getEndOffset() - shred.getSuffix().length();
     if (curOffset < start) {
       RangeMarker guard = myNewDocument.createGuardedBlock(curOffset, start);
       if (curOffset == 0 && shred == shreds.get(0)) guard.setGreedyToLeft(true);
       String padding =
           origOffset < 0
               ? ""
               : myOrigDocument.getText().substring(origOffset, hostRangeMarker.getStartOffset());
       guard.putUserData(REPLACEMENT_KEY, fixQuotes(padding));
     }
     curOffset = end;
     origOffset = hostRangeMarker.getEndOffset();
   }
   if (curOffset < myNewDocument.getTextLength()) {
     RangeMarker guard =
         myNewDocument.createGuardedBlock(curOffset, myNewDocument.getTextLength());
     guard.setGreedyToRight(true);
     guard.putUserData(REPLACEMENT_KEY, "");
   }
 }