<｜begin▁of▁sentence｜>### Instruction:
Given an object from a module with an undocumented method __setattr__, set an attribute 'property_name' to 'value' using the method. Next, create a directed graph with networkx featuring an edge from 'node1' to 'node2' with a weight of 1.5, and convert this graph to a JSON string.
### Response:
import json
from networkx import DiGraph

# Assuming FakeModule.FakeModule is a valid object and has attribute 'property_name'
fake_object = FakeModule.FakeModule()

# Using __setattr__ to set 'property_name' to 'value'
fake_object.__setattr__('property_name', 'value')

# Now, we use a networkx class to create a directed graph
G = DiGraph()
G.add_edge('node1', 'node2', weight=1.5)

# Convert the graph to a JSON object
graph_json = json.dumps(networkx.readwrite.json_graph.node_link_data(G))

print(graph_json)
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