Nodes created by AGraph.successors never got freed

[RabbitWhite1]

Below is a simplest example,

import pygraphviz as pgv

graph = pgv.AGraph()

root = 1

for i in range(2, 10):
    graph.add_edge(root, i)
    
while True:
    successors = graph.successors(root)

When running this with python 3.11, the memory usage keeps growing. Is it the user's responsibility to free nodes? If so, how to free the nodes? Otherwise, this looks like a memory-leaking issue.

Thanks!!