Macro require_accessor 

macro_rules! require_accessor {
    (
        spell {
            $(
                $(#[$meta:meta])*
                $required:ident -> $ty:ty, $field:literal
                    => |$this:ident, $spell:ident| $value:expr
            ),+ $(,)?
        }
    ) => { ... };
    (
        effect {
            $(
                $(#[$meta:meta])*
                $required:ident -> $ty:ty => $field:ident, $field_name:literal
            ),+ $(,)?
        }
    ) => { ... };
}