Returns a list of all nodes in this cluster as a mixed list of
        different node kinds.

        :return: list of :py:class:`Node`

def get_all_nodes(self):
        """Returns a list of all nodes in this cluster as a mixed list of
        different node kinds.

        :return: list of :py:class:`Node`
        """
        nodes = self.nodes.values()
        if nodes:
            return reduce(operator.add, nodes, list())
        else:
            return []