<｜begin▁of▁sentence｜>### Instruction:
Given a graph loaded from 'graph_data.gml', can you obtain and print the path length histogram and the number of unconnected vertex pairs assuming undirected paths?
### Response:
import igraph as ig

# Create an igraph Graph
graph = ig.Graph.Read_GML('graph_data.gml')

# Calculate the path length histogram of the graph
directed = False  # consider undirected paths
path_length_histogram, unconnected_pairs = graph.path_length_hist(directed=directed)

# Print the results
print('Path length histogram:', path_length_histogram)
print('Unconnected pairs:', unconnected_pairs)
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