code: protected static void removeViewer(Page page, IHelpViewer viewer, boolean close) {
          if (viewer != null && viewer == page.getAttribute(VIEWER_ATTRIB)) {
              removeViewer(page, close);
          }
      }
docs: Remove and optionally close the specified help viewer if is the active viewer for the
  specified page.
  
  @param page The page owner the help viewer.
  @param viewer The viewer to remove.
  @param close If true, close the help viewer after removing it.