1 digraph NamedAttributeGroup {

     2   mindist = 2.0

     3   1 -> 2 [label="annotation"]

     4   1 -> 4 [label="anyAttribute"]

     5   1 -> 3 [label="attribute"]

     6   1 -> 3 [label="attributeGroup"]

     7   2 -> 4 [label="anyAttribute"]

     8   2 -> 3 [label="attribute"]

     9   2 -> 3 [label="attributeGroup"]

    10   3 -> 4 [label="anyAttribute"]

    11   3 -> 3 [label="attribute"]

    12   3 -> 3 [label="attributeGroup"]

    13   1 [shape=doublecircle, style=filled, color=blue]

    14   2 [shape=doublecircle, style=filled, color=green]

    15   3 [shape=doublecircle, style=filled, color=green]

    16   4 [shape=doublecircle, style=filled, color=green]

    17 }