<｜begin▁of▁sentence｜>### Instruction:
Given two graphs with edge sets [(1, 2), (1, 3), (2, 3), (3, 4)] and [(5, 6), (5, 7), (7, 8), (6, 8)], can you determine if the two graphs could possibly be isomorphic?
### Response:
import networkx as nx

# Create two undirected graphs
G1 = nx.Graph()
G1.add_edges_from([(1, 2), (1, 3), (2, 3), (3, 4)])

G2 = nx.Graph()
G2.add_edges_from([(5, 6), (5, 7), (7, 8), (6, 8)])

# Use the function to check for possible isomorphism
could_be_iso = nx.fast_could_be_isomorphic(G1, G2)

print('Could G1 and G2 be isomorphic?', could_be_iso)
<|EOT|>
