@Override
	public void validate() {
		super.validate();
		if( connectionType == null ) {
			throw new IllegalStateException( "connectionType must not be null" );
		}
		if( source == null ) {
			throw new IllegalStateException( "source must not be null" );
		}
		if( target == null ) {
			throw new IllegalStateException( "target must not be null" );
		}
	}