Macro define_interceptor 

macro_rules! define_interceptor {
    (
		context: $context_name:ident<T>,
		trait: $trait_name:ident,
		fields: {
			$($field_name:ident: $field_type:ty),* $(,)?
		}
	) => { ... };
    (
		context: $context_name:ident,
		trait: $trait_name:ident<T>,
		fields: {
			$($field_name:ident: $field_type:ty),* $(,)?
		}
	) => { ... };
}

Generic macro to define interceptor contexts, traits, and chain execution