<｜begin▁of▁sentence｜>### Instruction:
Given a graph read from 'graph.gml', how can you use the VertexClustering.size_histogram method in igraph to obtain and print the histogram of cluster sizes after performing multilevel community detection?
### Response:
import igraph as ig

# Loading the graph (assuming 'graph.gml' is the file)
g = ig.Graph.Read_GML('graph.gml')

# Assume we have a VertexClustering object vc
# This is usually obtained by running some clustering algorithm
vc = g.community_multilevel()

# Now we can get the size histogram of these clusters
size_hist = vc.size_histogram()

# Printing the size histogram
for bin in size_hist:
    print(f'Size: {bin[0]}, Frequency: {bin[1]}')
<|EOT|>
