}
public BoundariesElementExpression( ElementCapture capture, TypeExpression.Topo topo )
{
super( capture,
new FlowElementExpression( Group.class, topo ),
new FlowElementExpression( Merge.class, topo ),
new FlowElementExpression( Boundary.class, topo ),
new FlowElementExpression( Tap.class, topo )
);
}