<｜begin▁of▁sentence｜>### Instruction:
Imagine you're designing a new level for your puzzle-adventure game, where players must connect different nodes (such as rooms or checkpoints) with paths (akin to edges). You've already established some paths: connecting Room 1 to Room 2, Room 1 to Room 3, Room 2 to Room 3, and Room 3 to Room 4.

Now, you'd like to introduce some potential expansions to the level by figuring out which additional paths can be created to ensure that all rooms are interconnected without any loops or duplications. This means you need to list all the potential paths that aren't already present in your level's design but could exist if the level were a completely interconnected network (a complete graph).

In developer terms, I'd like you to reframe the question as: "Which potential paths between rooms are currently missing in the level design, considering the existing rooms and paths?" This maintains the quest to identify all the absent connections without changing the semantics of the original question.
### Response:
import networkx as nx

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

# Find all nonexistent edges in the graph
nonexistent_edges = list(nx.non_edges(G))
print('Nonexistent edges:', nonexistent_edges)
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