Method first_name

2a_builder_pattern/rust/builder/src/main.rs:28–31

(mut self, first_name: impl Into<String>)

    }

    fn first_name(mut self, first_name: impl Into<String>) -> Self {
        self.first_name = Some(first_name.into());
        self
    }

    #[allow(dead_code)]
    fn last_name(mut self, last_name: impl Into<String>) -> Self {