Macro http::header::map::insert_phase_one

macro_rules! insert_phase_one {
    ($map:ident,
     $key:expr,
     $probe:ident,
     $pos:ident,
     $hash:ident,
     $danger:ident,
     $vacant:expr,
     $occupied:expr,
     $robinhood:expr) => { ... };
}