<｜begin▁of▁sentence｜>### Instruction:
Given a grid graph where the number of rows and columns should be squared before creating the graph, can you show a way to transform the number of rows parameter using a decorator provided by NetworkX, so that calling generate_grid_graph(3, 4) will actually produce a 9x4 grid graph?
### Response:
from networkx.utils import argmap

# Define a simple transformation function
def square(x):
    return x ** 2

# Apply the transformation to the 'n' parameter using the argmap decorator
@argmap(square, 'n')
def generate_grid_graph(n, m):
    return nx.grid_2d_graph(n, m)

# Now calling generate_grid_graph(3, 4) will actually generate a 9x4 grid graph
grid_graph = generate_grid_graph(3, 4)
nodes_count = len(grid_graph.nodes())
print('Number of nodes in the grid graph:', nodes_count)
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