def _init_sys_data(self, parent_path, probdata):
        super(Group, self)._init_sys_data(parent_path, probdata)
        self._sys_graph = None
        self._gs_outputs = None
        for sub in itervalues(self._subsystems):
            sub._init_sys_data(self.pathname, probdata)
Set the absolute pathname of each `System` in the tree.
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/core/group.py/Group._init_sys_data