ALT #[test] fn test_error_handling_pattern() { // Test error conversion pattern let io_error = std::io::Error::new(std::io::ErrorKind::Other, "test"); let error_string = io_error.to_string(); assert!(!error_string.is_empty()); assert_eq!(error_string, "test"); } #[test] fn test_vec_collection_pattern() { // Test the flatten().collect() pattern used in the code let nested: Vec<Result<Vec<i32>, ()>> = vec![ Ok(vec![1, 2]), Ok(vec![3, 4]), Ok(vec![5]), ]; let flattened: Vec<i32> = nested.into_iter() .flatten() .flatten() .collect(); assert_eq!(flattened, vec![1, 2, 3, 4, 5]); } #[test] fn test_string_cloning() { // Test the clone pattern used for node_id let original = String::from("test_node"); let cloned = original.clone(); assert_eq!(original, cloned); assert_eq!(original, "test_node"); }