code: private static void _initialFillSet (@Nonnull final ICommonsOrderedSet <String> aSet,
                                         @Nullable final String sItemList,
                                         final boolean bUnify)
    {
      ValueEnforcer.notNull (aSet, "Set");
      if (!aSet.isEmpty ())
        throw new IllegalArgumentException ("The provided set must be empty, but it is not: " + aSet);
  
      if (StringHelper.hasText (sItemList))
      {
        // Perform some default replacements to avoid updating all references at
        // once before splitting
        final String sRealItemList = StringHelper.replaceAll (sItemList,
                                                              EXTENSION_MACRO_WEB_DEFAULT,
                                                              "js,css,png,jpg,jpeg,gif,eot,svg,ttf,woff,woff2,map");
  
        for (final String sItem : StringHelper.getExploded (',', sRealItemList))
        {
          String sRealItem = sItem.trim ();
          if (bUnify)
            sRealItem = getUnifiedItem (sRealItem);
  
          // Add only non-empty items
          if (StringHelper.hasText (sRealItem))
            aSet.add (sRealItem);
        }
      }
    }
docs: Helper function to convert the configuration string to a collection.
  
  @param aSet
  The set to be filled. May not be <code>null</code>.
  @param sItemList
  The string to be separated to a list. Each item is separated by a
  ",".
  @param bUnify
  To unify the found item by converting them all to lowercase. This
  makes only sense for file extensions but not for file names. This
  unification is only relevant because of the case insensitive file
  system on Windows machines.