'Walk the tree of groups for a datacenter
:param datacenter: string - the datacenter to walk (ex: \'UC1\')
:return: a dictionary of groups and parents'

def _get_group_tree_for_datacenter(self, datacenter=None):

    self.root_group = self.clc.v2.Datacenter(location=datacenter).RootGroup()
    return self._walk_groups_recursive(parent_group=None, child_group=self.root_group)
