FreeFormConnection connection = peCreateService.createFreeFormConnection(diagram);
gaService.createPolyline(connection);
connection.setStart(sourceAnchor);
connection.setEnd(targetAnchor);

public class AddBendpointFeature extends DefaultAddBendpointFeature {

	public AddBendpointFeature(IFeatureProvider fp) {
		super(fp);
	}

	@Override
	public boolean canAddBendpoint(IAddBendpointContext context) {
		return false;
	}

	@Override
	public boolean canExecute(IContext context) {
		if (context instanceof IAddBendpointContext) {
			return canAddBendpoint((IAddBendpointContext) context);
		}
		return false;
	}
}

public class MoveBendpointFeature extends DefaultMoveBendpointFeature {
	
	public MoveBendpointFeature(IFeatureProvider fp) {
		super(fp);
	}

	@Override
	public boolean canMoveBendpoint(IMoveBendpointContext context) {
		return false;
	}

	@Override
	public boolean canExecute(IContext context) {
		if (context instanceof IMoveBendpointContext) {
			return canMoveBendpoint((IMoveBendpointContext) context);
		}
		return false;
	}
}

 (... in the FeatureProvider ...)

@Override
public IMoveBendpointFeature getMoveBendpointFeature(IMoveBendpointContext context) {
	return new MoveBendpointFeature(this);
}

@Override
public IAddBendpointFeature getAddBendpointFeature(IAddBendpointContext context) {
	return new AddBendpointFeature(this);
}