<｜begin▁of▁sentence｜>### Instruction:
As a Public Relations Specialist, you might be working with a tech company that has developed a new social networking platform. Your team wants to understand the process of reaching out to potential users in a systematic way. To help with this, you've been tasked with using the NetworkX library in Python to analyze the platform's connectivity. Specifically, you want to use the `bfsiter` function in NetworkX to obtain the vertices in breadth-first search order starting from a particular user's profile, representing vertex 0 in the graph. By understanding the order in which users could be reached based on this traversal, your team can develop more effective outreach strategies and engagement plans.
### Response:
import igraph as ig

# Create a graph
g = ig.Graph(edges=[(0, 1), (0, 2), (1, 3), (2, 3)])

# Create a BFS iterator starting from vertex 0
bfs_iter = g.bfsiter(0)

# Use the iterator to get the vertices in BFS order
vertices_in_bfs_order = [vertex.index for vertex in bfs_iter]
print(vertices_in_bfs_order)
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