code: public void setGroup(final CollapsibleGroup group) {
  		if (TabSetType.ACCORDION.equals(getType())) {
  			getOrCreateComponentModel().group = group;
  			group.addCollapsible(this);
  		}
  	}
docs: Set the {@link com.github.bordertech.wcomponents.CollapsibleGroup} that this component belongs to. This will
  enable a {@link com.github.bordertech.wcomponents.WCollapsibleToggle} component to target the tabset as part of
  the group.
  
  @param group the group to set