<｜begin▁of▁sentence｜>### Instruction:
Given a simple path graph with four nodes, using NetworkX's `generate_graphml` function, generate the GraphML representation as a pretty-printed string. Assume the path graph is created by `G = nx.path_graph(4)`.
### Response:
import networkx as nx

# Create a path graph with four nodes
G = nx.path_graph(4)

# Generate GraphML string
graphml_lines = list(nx.generate_graphml(G, prettyprint=True))

# Join the lines into a single string to print
graphml_str = '\n'.join(graphml_lines)
print(graphml_str)
<|EOT|>
