def add(self, node, conn_type):
        if node in self.children and conn_type == self.connector:
            return
        if len(self.children) < 2:
            self.connector = conn_type
        if self.connector == conn_type:
            if isinstance(node, Node) and (node.connector == conn_type or
                    len(node) == 1):
                self.children.extend(node.children)
            else:
                self.children.append(node)
        else:
            obj = self._new_instance(self.children, self.connector,
                    self.negated)
            self.connector = conn_type
            self.children = [obj, node]
Test listing issues.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/utils/tree.py/Node.add--crossover with--dataset/ETHPy150Open dustin/py-github/github/githubtest.py/IssueTest.testListIssues