code: public static Set<String> deserializeKeys(String foreignKeys)
      {
          Set<String> keys = new HashSet<String>();
  
          if (null == foreignKeys || foreignKeys.isEmpty())
          {
              return keys;
          }
  
          String array[] = foreignKeys.split(Constants.FOREIGN_KEY_SEPARATOR);
          for (String element : array)
          {
              keys.add(element);
          }
          return keys;
      }
docs: Splits foreign keys into Set.
  
  @param foreignKeys
  the foreign keys
  @return the set