Add benchmarks for common_neighbors.

benchmarks/benchmarks/benchmark_neighbors.py

@@ -29,3 +29,23 @@ def time_path_last(self, num_nodes):
 
     def time_path_center(self, num_nodes):
         set(nx.non_neighbors(self.path_graph, num_nodes // 2))
+
+
+# NOTE: explicit set construction in benchmarks is required for meaningful
+# comparisons due to change in return type from generator -> set. See gh-7244.
+class CommonNeighbors:
+    param_names = ["num_nodes"]
+    params = [10, 100, 1000]
+
+    def setup(self, num_nodes):
+        self.star_graph = nx.star_graph(num_nodes)
+        self.complete_graph = nx.complete_graph(num_nodes)
+
+    def time_star_center_rim(self, num_nodes):
+        set(nx.common_neighbors(self.star_graph, 0, num_nodes // 2))
+
+    def time_star_rim_rim(self, num_nodes):
+        set(nx.common_neighbors(self.star_graph, 4, 5))
+
+    def time_complete(self, num_nodes):
+        set(nx.common_neighbors(self.complete_graph, 0, num_nodes // 2))