def buildDSAndSpeciesTree(self):
"""Build one valid DS-tree for the relationships given, and a species tree with which it is consistent, and returns both trees.
If no such pair of trees can be built, returns False instead.
The DS-tree built prioritizes dups first.
"""
startcc = self.genes.copy()
dstree = TreeNode()
dstree.set = set(startcc)
dsNodeList =[dstree]
constructedSpeciesTree = TreeNode()
constructedSpeciesTree.set = set(self.treelessGeneSpeciesMapping[x] for x in startcc)
hasPassed = self._buildDSAndSpeciesTree(startcc, dsNodeList, constructedSpeciesTree)
#Return dstree and species tree as an ordered pair
treepair = [dstree, constructedSpeciesTree]
#in case you are wondering, what's below is (hasPassed ? treepair : False)
return (treepair if hasPassed else False)
