You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: 359_deserialize_seed.rs
    path of file: ./repos/ron/tests
    
    the code of the file until where you have to start completion: #[test]
fn test_deserialize_seed() {
    // Test adapted from David Tolnay's serde-yaml:
    // https://github.com/dtolnay/serde-yaml/blob/8a806e316302fd2e6541dccee6d166dd51b689d6/tests/test_de.rs#L357-L392

    struct Seed(i64);

    impl<'de> serde::de::DeserializeSeed<'de> for Seed {
        type Value = i64;

        fn deserialize<D>(self, deserializer: D) -> Result<i64, D::Error>
        where
            D: serde::de::Deserializer<'de>,
        {
            struct Visitor(i64);

            impl<'de> serde::de::Visitor<'de> for Visitor {
                type Value 
    
fn test_deserialize_seed() {
    // Test adapted from David Tolnay's serde-yaml:
    // https://github.com/dtolnay/serde-yaml/blob/8a806e316302fd2e6541dccee6d166dd51b689d6/tests/test_de.rs#L357-L392

    struct Seed(i64);

    impl<'de> serde::de::DeserializeSeed<'de> for Seed {
        type Value = i64;

        fn deserialize<D>(self, deserializer: D) -> Result<i64, D::Error>
        where
            D: serde::de::Deserializer<'de>,
        {
            struct Visitor(i64);

            impl<'de> serde::de::Visitor<'de> for Visitor {
                type Value = i64;

                fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                    write!(formatter, "an integer")
                }

                fn visit_i64<E: serde::de::Error>(self, v: i64) -> Result<i64, E> {
                    Ok(v * self.0)
                }

                fn visit_u64<E: serde::de::Error>(self, v: u64) -> Result<i64, E> {
                    Ok(v as i64 * self.0)
                }
            }

            deserializer.deserialize_any(Visitor(self.0))
        }
    }

    let cases = [("3", 5, 15), ("6", 7, 42), ("-5", 9, -45)];

    for &(ron, seed, expected) in &cases {
        let deserialized = ron::Options::default()
            .from_str_seed(ron, Seed(seed))
            .unwrap();

        assert_eq!(expected, deserialized);
    }

    assert_eq!(
        ron::Options::default().from_str_seed("'a'", Seed(42)),
        Err(ron::error::SpannedError {
            code: ron::Error::InvalidValueForType {
                expected: String::from("an integer"),
                found: String::from("the string \"a\""),
            },
            position: ron::error::Position { line: 1, col: 4 },
        })
    );
}