tip="scala.Product"] ;
  node3 [label="Serializable", id="graph1_3", class="default", tooltip="java.io.Serializable"] ;
  node1 -> node0 [arrowtail="empty", dir="back", id="graph1_1_0", class="inheritance", tooltip="SP is a subtype of SententialPhrase"] ;node2 -> node0 [arrowtail="empty", dir="back", id="graph1_2_0", class="inheritance", tooltip="SP is a subtype of Product"] ;node3 -> node0 [arrowtail="empty", dir="back", id="graph1_3_0", class="inheritance", tooltip="SP is a subtype of Serializable"] ;
}
<