Macro define_closure_interceptor 

macro_rules! define_closure_interceptor {
    (
		$wrapper_name:ident,
		$trait_name:ident,
		$context_type:ident,
		with_transaction
	) => { ... };
    (
		$wrapper_name:ident,
		$trait_name:ident,
		$context_type:ident,
		no_transaction_param
	) => { ... };
}

Macro to generate closure interceptor wrapper types