Get a list of workgroup nodes.

def list(self, wg_uuid, parent=None, flat=False, node_types=None):
        """ Get a list of workgroup nodes."""
        url = "%(base)s/%(wg_uuid)s/nodes" % {
            'base': self.local_base_url,
            'wg_uuid': wg_uuid
        }
        param = []
        if parent:
            # I use only the last folder uuid, the first ones are not really useful
            if isinstance(parent, (list,)):
                if len(parent) >= 1:
                    parent = parent[-1]
            param.append(("parent", parent))
        if flat:
            param.append(("flat", True))
        if node_types:
            for node_type in node_types:
                param.append(("type", node_type))
        encode = urllib.urlencode(param)
        if encode:
            url += "?"
            url += encode
        return self.core.list(url)