<｜begin▁of▁sentence｜>### Instruction:
Given a graph which you can read from graph_data.gml, can you use the subgraph method from a CohesiveBlocks object in igraph to get a subgraph of a specific cohesive block in the graph, and print the number of vertices and edges in that subgraph?
### Response:
import igraph as ig

# Read a graph from a file
graph = ig.Graph.Read_GML('graph_data.gml')

# Create a cohesive block object
cohesive_blocks = graph.community_optimal_modularity().as_cover().cliques(min=2)

# Get the subgraph belonging to the first cohesive block
subgraph = cohesive_blocks.subgraph(0)

# Print basic information about the subgraph
print('Number of vertices in subgraph:', subgraph.vcount())
print('Number of edges in subgraph:', subgraph.ecount())
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