package org.apache.commons.graph;

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 * The Apache Software License, Version 1.1
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/**
 * Graph This is the basic interface for a graph. G = { v, e }
 * getAdjacentVertices and getAdjacentEdges helps to define the behavior of
 * Edges.
 */

import java.util.Set;

/**
 * Description of the Interface
 */
public interface Graph
{
    /**
     * getVertices - Returns the total set of Vertices in the graph.
     */
    public Set getVertices();

    /**
     * getEdges - Returns the total set of Edges in the graph.
     */
    public Set getEdges();

    /**
     * getEdges( Vertex ) - This method will return all edges which touch this
     * vertex.
     */
    public Set getEdges(Vertex v);

    /**
     * getVertices( Edge ) - This method will return the set of Verticies on
     * this Edge. (2 for normal edges, > 2 for HyperEdges.)
     */
    public Set getVertices(Edge e);
}