<｜begin▁of▁sentence｜>### Instruction:
As a Quality Assurance Analyst, you're tasked with ensuring that software functions correctly and meets user expectations. Imagine you're testing a social networking platform. Your goal is to assess the network's connectivity by determining how many users can be reached from a particular user within one interaction.

Given a network of users connected by friendships, represented by undirected edges between nodes, your task is to use NetworkX, a Python library for network analysis, to calculate the number of users reachable from a specific user in just one step. 

For instance, let's say you have a network where users are nodes, and friendships are edges. If user 1 is friends with users 2 and 3, and user 2 is also friends with user 4, you need to find out how many users can be reached directly from user 1 through one friendship connection.

Now, leveraging NetworkX's functionality, you'll determine the number of users reachable from user 1 in exactly one step and report this value for further evaluation.
### Response:
import networkx as nx

# Create a simple undirected graph
G = nx.Graph()
G.add_edges_from([(0, 1), (0, 2), (1, 2), (1, 3), (3, 4)])

# Use neighborhood_size to get the number of vertices reachable within 1 step from node 1
reachable_nodes_order_1 = G.neighbors(1)

# Print the result
print('Number of vertices reachable from node 1 in 1 step:', len(list(reachable_nodes_order_1)))
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