code: public static <T> String stringImg(Collection<T> coll) {
  	StringBuffer buffer = new StringBuffer();
  
  	buffer.append("[ ");
  	for(T t : sortedCollection(coll)) {
  	    buffer.append(t);
  	    buffer.append(" ");
  	}
  	buffer.append("]");
  
  	return buffer.toString();
      }
docs: Returns a string representation of all elements from a
  collection, in increasing lexicographic order of their string
  representations.