code: public CloseableIterator<CaptureSearchResult> getPrefixReverseIterator(String prefix)
  			throws ResourceIndexNotAvailableException {
  
  		if(getState() != STATE_SYNCHED) {
  			throw new ResourceIndexNotAvailableException("Not synchronized");
  		}
  		return super.getPrefixReverseIterator(prefix);
  	}
docs: /*
  (non-Javadoc)
  
  @see org.archive.wayback.resourceindex.SearchResultSource#getPrefixReverseIterator(java.lang.String)