pub fn print_with_prefix(b: &BigInt, prefix: String) {
//@ The syntax for closures is `|arg1, arg2, ...| code`. Notice that the closure can reference variables like `prefix` that it did not
//@ take as argument - variables that happen to be present *outside* of the closure. We say that the closure *captures*
pub fn print_with_prefix(b: &BigInt, prefix: String) {
//@ The syntax for closures is `|arg1, arg2, ...| code`. Notice that the closure can reference variables like `prefix` that it did not
//@ take as argument - variables that happen to be present *outside* of the closure. We say that the closure *captures*