code: public static String keyHash(Struct sct) {
  	Key[] keys;
  	Arrays.sort(keys = CollectionUtil.keys(sct));
  
  	StringBuilder sb = new StringBuilder();
  	for (int i = 0; i < keys.length; i++) {
  	    sb.append(keys[i].getString()).append(';');
  	}
  	return Long.toString(HashUtil.create64BitHash(sb), Character.MAX_RADIX);
      }
docs: creates a hash based on the keys of the Map/Struct
  
  @param map
  @return