PhyloTreeNode c;
do{ c = nodes.someElement();}
while (c.getTaxonLabel()==null);
searchResult = false;
if (c.haveABCTopology(a, b)) {
TaxonVariant as = a.getTaxonLabel().getTaxonVariant();
TaxonVariant bs = b.getTaxonLabel().getTaxonVariant();
TaxonVariant cs = c.getTaxonLabel().getTaxonVariant();
logger.debug("Searching for trees with a=" + as + ", b=" + bs + ", c=" + cs);