code: private void checkPlaceholderVisibility(I_CmsDropTarget target) {
  
          if (target instanceof I_CmsDropContainer) {
              I_CmsDropContainer container = (I_CmsDropContainer)target;
              container.setPlaceholderVisibility(
                  (container != m_initialDropTarget)
                      || ((m_currentIndex - m_originalIndex) > 1)
                      || ((m_originalIndex - m_currentIndex) > 0));
          }
      }
docs: Checks and sets if the place holder should be visible.<p>
  
  @param target the target container