How to add node attribute after a graph has been created

Hello everyone,

I would like to add a node attribute attribute to a graph after it has been created.
I tried using something like['attribute'] = [1,2,3,4]. However, graph.columns() does not reflect that change and as a result my program shows the error message

(BAD_COLUMN_NAME): Glyph refers to nonexistent column name. This could either be due to a misspelling or typo, or due to an expected

How do I add attribute correctly AFTER the graph has been created? (meaning how do I get graph.columns() to display my added attribute).

A small example for a graph (though without the error message) is

import numpy as np
import holoviews as hv

# set up the graph 
node_indices = np.arange(3, dtype=np.int32)
source = np.zeros(3, dtype=np.int32)
target = node_indices
# create graph
x, y = [0, 1, 1], [0, 1, 2]  # some coordinates
nodes = hv.Nodes((x, y, node_indices),)
graph = hv.Graph(((source, target), nodes))

# add an attribute after the graph has been created["attribute"] = [1,2,3]
# result: 
#   x  y  index  attribute
#0  0  0      0          1
#1  1  1      1          2
#2  1  2      2          3

# result: OrderedDict([('x', array([0, 1, 1])), ('y', array([0, 1, 2])), ('index', array([0, 1, 2], dtype=int32))])

If you have any ideas, please let me know. Thanks in advance!