if (n instanceof BlockStartNode) {
BlockStartNode sn = (BlockStartNode) n;
w.printf("%s [shape=trapezium]%n", n.getId());
} else
if (n instanceof BlockEndNode) {
BlockEndNode sn = (BlockEndNode) n;
w.printf("%s [shape=invtrapezium]%n", n.getId());
w.printf("%s -> %s [style=dotted]%n",
sn.getStartNode().getId(), n.getId());
}
w.printf("%s [label=\"%s: %s\"]%n", n.getId(), n.getId(), n.getDisplayName());
}