<｜begin▁of▁sentence｜>### Instruction:
Suppose you have a directed graph with nodes A, B, C, and D. The edge set, with weights, is [('A', 'B', 3), ('B', 'C', 1), ('A', 'C', 5), ('C', 'D', 2)]. You are given a flowDict representing the flow along these edges, and you want to compute the total cost of this flow using NetworkX. The flowDict is {'A': {'B': 2, 'C': 1}, 'B': {'C': 2}, 'C': {'D': 3}, 'D': {}}. How would you calculate the cost of this flow using the cost_of_flow function provided by NetworkX?
### Response:
import networkx as nx

# Create a directed graph
G = nx.DiGraph()

# Add edges with weights
G.add_edge('A', 'B', weight=3)
G.add_edge('B', 'C', weight=1)
G.add_edge('A', 'C', weight=5)
G.add_edge('C', 'D', weight=2)

# Define a flow dictionary
flowDict = {'A': {'B': 2, 'C': 1}, 'B': {'C': 2}, 'C': {'D': 3}, 'D': {}}

# Compute the cost of the flow
flow_cost = nx.cost_of_flow(G, flowDict)

print(f'The cost of the flow is: {flow_cost}')
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