code: protected static String getStartedWord(String str, int pos){
  		assert(pos < str.length() && pos >= 0);
  
  		if(	posIsAtWordStart(str, pos) ){
  			int nextSpace = findNextNonLetterOrDigit(str, pos);
  			if(nextSpace == -1){
  				nextSpace = str.length();
  			}
  			
  			return str.substring(pos, nextSpace);
  		}
  		return null;
  	}
docs: If pos is starting a new word in str, returns this word.
  Else, returns null.