code: protected void initUserObject() {
  
          if (m_indexsource == null) {
              try {
                  m_indexsource = m_searchManager.getIndexSource(getParamIndexsource());
                  if (m_indexsource == null) {
                      m_indexsource = new CmsSearchIndexSource();
                  }
              } catch (Exception e) {
                  m_indexsource = new CmsSearchIndexSource();
              }
          }
      }
docs: Initializes the user object to work with depending on the dialog state and request parameters.<p>
  
  Two initializations of the user object on first dialog call are possible:
  <ul>
  <li>edit an existing search index</li>
  <li>create a new search index with default initialization</li>
  </ul>