Macro domain_error 

macro_rules! domain_error {
    (
        $(#[$emeta:meta])*
        pub enum $name:ident {
            common: [ $($common:ident),* $(,)? ]
            $(, $($body:tt)*)?
        }
    ) => { ... };
    (
        $(#[$emeta:meta])*
        pub enum $name:ident {
            $($body:tt)*
        }
    ) => { ... };
}