@Override
	public String toString() {

		String s = "\n";
		String[] vertices = symbolTable.keys();
		for (int v = 0; v < vertices.length; v++) {
			AdjacencyList AdjacencyList = (AdjacencyList) symbolTable
					.get(vertices[v]);
			s += vertices[v] + ": " + AdjacencyList + "\n";
		}
		return s;
	}