<｜begin▁of▁sentence｜>### Instruction:
Given a graph object, determine if it has at least one vertex. Use the __bool__ method to check the existence of vertices in the graph and print the result.
### Response:
import networkx as nx

# Create an empty graph and a non-empty graph
empty_g = nx.Graph()
non_empty_g = nx.Graph()
non_empty_g.add_node(1)  # Adding a node to make it non-empty

# Check if the graphs are non-empty using __bool__
print(bool(empty_g))  # Expected output: False
print(bool(non_empty_g))  # Expected output: True
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