docs: public int indexOfFromTo(Object element, int from, int to, boolean testForEquality) {
  	if (size==0) return -1;
  	checkRangeFromTo(from, to, size);
  
  	Object[] theElements = elements;
  	if (testForEquality && element!=null) {
  		for (int i = from ; i <= to; i++) {
  		    if (element.equals(theElements[i])) {return i;} //found
  		}
  
  	}
  	else {
  		for (int i = from ; i <= to; i++) {
  		    if (element==theElements[i]) {return i;} //found
  		}
  	}
  	return -1; //not found
  }