 literal"><span class="pre">EdgeIterator</span></tt> must be a <tt class="docutils literal"><span class="pre">std::pair</span></tt>, where the type in the pair is an
integer type. The integers will correspond to vertices, and they must
all fall in the range of <tt class="docutils literal"><span class="pre">[0,</span> <span class="pre">n)</span></tt>. When provided, <tt class="docutils literal"><span class="pre">ep_iter</span></tt>
refers to an edge property list <tt class="docutils literal"><span class="pre