<｜begin▁of▁sentence｜>### Instruction:
Given the power grid graph which you can read from a GML file named power.gml, can you use the CoAch function in cdlib with default parameters to perform community detection? And can you generate a JSON representation of the resulting NodeClustering object?
### Response:
import networkx as nx
from cdlib import algorithms

# Read the power grid graph
G = nx.read_gml('power.gml')

# Apply the CoAch algorithm for community detection
coms = algorithms.coach(G, density_threshold=0.7, affinity_threshold=0.225, closeness_threshold=0.5)

# Generate a JSON representation of the NodeClustering object
coms_json = coms.to_json()

print(coms_json)
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