>num_vertices(g)</tt> and using the <tt>i_map</tt> for the index
  map.<br>
  <b>Python</b>: Unsupported parameter.
</blockquote>

UTIL: <tt>color_map(ColorMap c_map)</tt>
<blockquote>
  This is used by the algorithm to keep track of its progress through
  the graph. The type <tt>ColorMap</tt> must be a model of <a
  href="../../property_map/doc/ReadWritePropertyMap.html">Read/Write
  Property Map</a> and its key type must be the graph's vertex
  descriptor type and the value type of the color map must mode