<｜begin▁of▁sentence｜>### Instruction:
Given two separate graphs, the first consisting of edges (1, 2) and (2, 3), and the second consisting of edges (4, 5) and (5, 6), how can one use the __iadd__ method in NetworkX to create a single graph that represents the disjoint union of these two graphs, and print out the edges of the resulting graph?
### Response:
import networkx as nx

# Create two graphs
g1 = nx.Graph()
g1.add_edges_from([(1, 2), (2, 3)])
g2 = nx.Graph()
g2.add_edges_from([(4, 5), (5, 6)])

# Use the in-place addition to combine the graphs
g1 += g2

# Print the edges of the combined graph
print(g1.edges())
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