hi everybody! I just want to store a BigUint constant that will be used in many functions of my Smart Contract. There are two ways of doing this: - define a Rust constant of type u64 named RAY and in each function where it is needed declare let ray = BigUint::from(RAY) - declare the BigUint once (in the constructor for example) and store it in a mapper. Retrieve the mapper value in every function the constant value is needed. which approach is better?