def METHOD_NAME(self, num_nodes=100):
    """
    Creates the specified number of ContentNode objects, and returns the time taken.
    :param num_nodes: Number of nodes to create.
    :return: Time taken in seconds to perform the operation.
    """
    # Allow calling this method multiple times
    current_nodes = ContentNode.objects.count()
    parent = self.root_node
    start = time.time()
    for i in range(num_nodes):
        node = ContentNode.objects.create(title="test_server_perf Node {}".format(i), parent=parent, kind=self.topic)
        # try to create a multi-level tree structure to better test tree recalc operations
        if num_nodes > 20:
            if i % (num_nodes / 10) == 0:
                sys.stdout.write('.')
                sys.stdout.flush()
                parent = node
    elapsed = time.time() - start
    if ContentNode.objects.count() != current_nodes + num_nodes:
        raise AssertionError
    return elapsed