src/main/java/com/googlecode/javaewah/NonEmptyVirtualStorage.java
@Override
    public void addStreamOfLiteralWords(Buffer buffer, int start, int number) {
        for(int x = start; x < start + number ; ++x)
           if(buffer.getWord(x)!=0) throw nonEmptyException;
    }
@Override
    public void addStreamOfLiteralWords(Buffer buffer, int start, int number) {
        for(int x = start; x < start + number ; ++x)
           if(buffer.getWord(x)!=0) throw nonEmptyException;
    }
throws a NonEmptyException exception when number is greater than 0