Macro EndpointDef 

macro_rules! EndpointDef {
    ( $(#[$docs:meta])* $pub:vis $name:ident($in:ty),
    // We just ignore any documentation for success cases: there is
    // nowhere we can put it.
    Ok => $out:ty, [$($(#[$ok_docs:meta])* $ok_status:ident,)*],
    Err => $err:ident, [$($(#[$err_docs:meta])* $err_status:ident => $variant:ident,)*],
    ConversionErr => $conv_err:ty,
    ApiErr => $api_err:ty,
    $($defs:tt)* ) => { ... };
}

A macro used for defining the properties for a request to a particular HTTP endpoint.