diff --git a/src/generators.rs b/src/generators.rs
index d257851..774e317 100644
--- a/src/generators.rs
+++ b/src/generators.rs
@@ -39,7 +39,11 @@ mod tests {
     fn petersen() {
         let mut graph = AppendGraph::new();
         let (vertices, edges) = super::petersen(&mut graph);
-        assert_eq!(graph.vertex_count(), 10, "unexpected number of added vertices");
+        assert_eq!(
+            graph.vertex_count(),
+            10,
+            "unexpected number of added vertices"
+        );
         assert_eq!(graph.edge_count(), 15, "unexpected number of added edges");
         assert!(
             graph.vertices().all(|v| graph.degree(v) == 3),