code: public static boolean isEndGroupKey(RenderingHints.Key key) {
          return SVGHints.KEY_END_GROUP.equals(key) || endGroupKeys.contains(key);        
      }
docs: Returns {@code true} if this key is equivalent to
  {@link #KEY_END_GROUP}, and {@code false} otherwise.  The purpose
  of this method is to allow certain keys from external packages (such as
  JFreeChart and Orson Charts) to use their own keys to drive the
  behaviour of {@code SVGHints.KEY_END_GROUP}.  This has two benefits:
  (1) it avoids the necessity to make JFreeSVG a direct dependency, and
  (2) it makes the grouping behaviour generic from the point of view of
  the external package, rather than SVG-specific.
  
  @param key  the key ({@code null} not permitted).
  
  @return A boolean.
  
  @since 1.8