code: private void initialize(
          Collection<String> toRemove,
          Collection<String> toAdd,
          String siteRoot,
          boolean removeAllNonExplicitlyAdded) {
  
          m_removeAllNonExplicitlyAdded = removeAllNonExplicitlyAdded;
  
          for (String removeKey : toRemove) {
              if (CmsUUID.isValidUUID(removeKey)) {
                  m_updateSet.put(new CmsUUID(removeKey), Boolean.FALSE);
              } else if (removeKey.startsWith(PREFIX_TYPE)) {
                  m_typeUpdateSet.put(removePrefix(removeKey), Boolean.FALSE);
              }
          }
          for (String addKey : toAdd) {
              if (CmsUUID.isValidUUID(addKey)) {
                  m_updateSet.put(new CmsUUID(addKey), Boolean.TRUE);
              } else if (addKey.startsWith(PREFIX_TYPE)) {
                  m_typeUpdateSet.put(removePrefix(addKey), Boolean.TRUE);
              }
          }
          if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(siteRoot)) {
              if (!siteRoot.endsWith("/")) {
                  siteRoot += "/";
              }
              String regex = "^(/system/|" + OpenCms.getSiteManager().getSharedFolder() + "|" + siteRoot + ").*";
  
              m_pathPattern = Pattern.compile(regex);
          }
      }
docs: Initializes this formatter change set with the values from the sitemap configuration.<p>
  
  @param toRemove the keys for the formatters to remove
  @param toAdd the keys for the formatters to add
  @param siteRoot the site root of the current config
  @param removeAllNonExplicitlyAdded flag, indicating if all formatters that are not explicitly added should be removed