java.io.Serializable { private String label; java.util.List children; java.util.List parents; public void Vertex(String); public String getLabel(); public void addEdgeTo(Vertex); public void removeEdgeTo(Vertex); public void addEdgeFrom(Vertex); public void removeEdgeFrom(Vertex); public java.util.List getChildren(); public java.util.List getChildLabels(); public java.util.List getParents(); public java.util.List getParentLabels(); public boolean isLeaf(); public boolean isRoot(); public boolean isConnected();...