match<A> method
Given 2 functions (one for the Ok variant and one for the Err variant)
execute the function that matches the Result variant.
Match callbacks do not necessitate to return a Result, however you can
return a Result if you want to.
match is like chaining map and mapErr, with the distinction that
with match both functions must have the same return type.
@param ok
@param err
Implementation
@override
A match<A>(A Function(T t) ok, A Function(E e) err) => ok(this.value);