def resolveRootNode(self):
        length = len(self.nodeList)
        
        if 0 > length:
            activeNode = None
            for node in self.nodeList:
                assert type(node) is PomTreeNode
                if activeNode != None:
                    act = self.resolveNodeRelations(node)
                    if act != activeNode:
                        logging.error("Multiple root nodes encountered")
                        raise PomParseError("Resolution of RootNode failed as the structure contains multiple trees")
                else:
                    activeNode = self.resolveNodeRelations(node)
        else:
            raise PomParseError("Resolution of RootNode failed as the structure is empty")
dataset/ETHPy150Open w-mg-moorhouse/PyPomVisualiser/pypomvisualiser/pom/TreeCreation.py/TreeCreation.resolveRootNode/swapped operands of `>`