trait RequestSession {
    // Required methods
    fn get_session_token(&mut self) -> Option<String>;
    fn require_session_token(&mut self) -> IronResult<String>;
    fn expect_session_token(&mut self) -> IronResult<String>;
}trait RequestSession {
    // Required methods
    fn get_session_token(&mut self) -> Option<String>;
    fn require_session_token(&mut self) -> IronResult<String>;
    fn expect_session_token(&mut self) -> IronResult<String>;
}