refactor: use networkx traversal instead of homebrew

prereise/gather/griddata/hifld/data_access/load.py

@@ -261,26 +261,18 @@ def _generate_linear_spanning_tree(segments):
             # The minimum spanning tree wasn't good, go to the next iteration
             pass
 
-    # Identify an endpoint of the minimum spanning tree
+    # Identify an endpoint of the linear minimum spanning tree
     node_degrees = dict(nx.degree(tree))
     endpoint = min(k for k, v in node_degrees.items() if v == 1)
-    last_endpoint = None
     # Traverse the tree, adding segments in order
     joined_segments = []
-    while True:
-        next_endpoints = list(set(tree[endpoint]) - {last_endpoint})
-        assert len(next_endpoints) == 1
-        next_endpoint = next_endpoints[0]
-        (seg1, which1), (seg2, _) = endpoint, next_endpoints[0]
+    traversal = nx.algorithms.traversal.dfs_edges(tree, source=endpoint)
+    for (seg1, which1), (seg2, _) in traversal:
         if seg1 == seg2:
             if which1 == "start":
                 joined_segments += linear_segments[seg1]
             else:
                 joined_segments += linear_segments[seg1][::-1]
-        if node_degrees[next_endpoint] == 1:
-            break
-        last_endpoint = endpoint
-        endpoint = next_endpoint
 
     return joined_segments