package graph;
import java.util.Iterator;

/** A directed graph in which each vertex stores its outgoing edges. */

public class AdjListDigraph implements Digraph {  

  // ---------- INSTANCE VARIABLES ----------

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  // ---------- CONSTRUCTORS ----------

  /* Creates an empty graph.  The user can add vertices and edges to it. */
  public AdjListDigraph() {
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  }

  // ---------- METHODS IMPLEMENTING DIGRAPH ----------

  public int numVertices() { 
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  }
  public int numEdges() { 
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  }

  public Iterator outIncidentEdges(Vertex v) {
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  }

  public Vertex insertVertex(Object element) {
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  }
    
  public DirectedEdge insertDirectedEdge(Vertex from, Vertex to, Object element) {
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  }

  public void insertReverseOf(DirectedEdge e) {
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  }
}