<a name="l00131"></a><span class="lineno">  131</span>&#160;        <span class="keywordtype">bool</span> hasPredecessors() <span class="keyword">const</span>;</div><div class="line"><a name="l00132"></a><span class="lineno">  132</span>&#160;</div><div class="line"><a name="l00133"></a><span class="lineno">  133</span>&#160;        <span class="keywordtype">size_t</span> cardinality() <span class="keyword">const</span>;</div><div class="line"><a name="l00134"></a><span class="lineno">  134</span>&#160;</di