ent data structures). The third argument, <tt>bidirectionalS</tt>,
selects a directed graph that provides access to both out and in-edges. The
other options for the third argument are <tt>directedS</tt> which selects a
directed graph with only out-edges, and <tt>undirectedS</tt> which selects an
undirected graph.
<p>Once we have the graph type selected, we can create the graph in <a href="#fig:quick-start">Figure
2</a> by declaring a graph object and filling in edges using the <a href="MutableGraph.html#sec