question: public static Window windowForWordInPosition ( int windowSize , int wordPos , List < String > sentence ) { List < String > window = new ArrayList < > ( ) ; List < String > onlyTokens = new ArrayList < > ( ) ; int contextSize = ( int ) Math . floor ( ( windowSize - 1 ) / 2 ) ; for ( int i = wordPos - contextSize ; i <= wordPos + contextSize ; i ++ ) { if ( i < 0 ) window . add ( "<s>" ) ; else if ( i >= sentence . size ( ) ) window . add ( "</s>" ) ; else { onlyTokens . add ( sentence . get ( i ) ) ; window . add ( sentence . get ( i ) ) ; } } String wholeSentence = StringUtils . join ( sentence ) ; String window2 = StringUtils . join ( onlyTokens ) ; int begin = wholeSentence . indexOf ( window2 ) ; int end = begin + window2 . length ( ) ; return new Window ( window , begin , end ) ; }
target:  Creates a sliding window from text