##Clusters
##cluster style
##In original graphviz defining a subgraph whose name begins with "cluster_" will make it visible. Msc-generator introduces the 'cluster' keyword so you do not have to dance around it.
graph {
    rankdir = LR;
    subgraph cluster_one {
        label="Cluster one";
        style=rounded;
        style=filled;
        one1->one2;
    } => two;
    cluster Three {
    	style="rounded,filled";
    	three1->three2;
    } => two;
};