code: @Override
      public Object getDefaultValue(Class<?> hint) {
          return (hint == null ||
                  hint == ScriptRuntime.ScriptableClass ||
                  hint == ScriptRuntime.FunctionClass) ?
              this : getDelegee().getDefaultValue(hint);
      }
docs: Note that this method does not get forwarded to the delegee if
  the <code>hint</code> parameter is null,
  <code>ScriptRuntime.ScriptableClass</code> or
  <code>ScriptRuntime.FunctionClass</code>. Instead the object
  itself is returned.
  
  @param hint the type hint
  @return the default value
  
  @see org.mozilla.javascript.Scriptable#getDefaultValue