<｜begin▁of▁sentence｜>### Instruction:
Assuming you have a Configuration class that allows setting various options, and you want to set 'layout_engine' for a graph layout configuration to 'dot', which is one of Graphviz's layout engines. How would you use the Configuration.__setitem__ method to set this option and then apply it to a NetworkX graph to plot it using the dot layout from Graphviz?
### Response:
from networkx.drawing.nx_agraph import GraphvizLayout
import matplotlib.pyplot as plt
import networkx as nx

# Configuration mock class (since we don't have the actual library or class)
class Configuration:
    def __init__(self):
        self.config = {}

    def __setitem__(self, item, value):
        self.config[item] = value

config = Configuration()
config['layout_engine'] = 'dot'

# Assuming we want to apply the configuration to a Graphviz layout in NetworkX
g = nx.complete_graph(5)
pos = GraphvizLayout(g, prog=config['layout_engine']).layout()
nx.draw(g, pos=pos, with_labels=True)
plt.show()
<|EOT|>
