1: public boolean isEmpty() 2: { 3: return vertices.isEmpty(); 4: } // end isEmpty 5: 6: public void clear() 7: { 8: vertices.clear(); 9: edgeCount = 0; 10: } // end clear 11: 12: public int getNumberOfVertices() 13: { 14: return vertices.getSize(); 15: } // end getNumberOfVertices 16: 17: public int getNumberOfEdges() 18: { 19: return edgeCount; 20: } // end getNumberOfEdges 21: // Version 4.0