Bug 312761 It makes no difference changing the series labels position in Radar chart.[13]
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/type/impl/PieSeriesImpl.java
rotation = newRotation;
		boolean oldRotationESet = rotationESet;
		rotationESet = true;
		if ( eNotificationRequired( ) )
			eNotify( new ENotificationImpl( this,
					Notification.SET,
					TypePackage.PIE_SERIES__ROTATION,
					oldRotation,
					rotation,
					!oldRotationESet ) );
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public void unsetRotation( )
	{
		double oldRotation = rotation;
		boolean oldRotationESet = rotationESet;
		rotation = ROTATION_EDEFAULT;
		rotationESet = false;
		if ( eNotificationRequired( ) )
			eNotify( new ENotificationImpl( this,
					Notification.UNSET,
					TypePackage.PIE_SERIES__ROTATION,
					oldRotation,
					ROTATION_EDEFAULT,
					oldRotationESet ) );
	}