br>
  <b>Default:</b> <tt>dummy_property_map</tt><br>

  <b>Python</b>: Must be a <tt>vertex_vertex_map</tt> for the graph.<br>
</blockquote>

UTIL/OUT: <tt>distance_map(DistanceMap distance_map)</tt> 
<blockquote>
  The shortest path weight from the source vertex <tt>start_vertex</tt> to each
  vertex in the graph <tt>graph</tt> is recorded in this property map. The
  shortest path weight is the sum of the edge weights along the
  shortest path.  The type <tt>DistanceMap</tt> must be a model of <a
  href="