operator & method
Combines two already-evaluated results using the and operator (&).
Shorthand for calling and. Returns this result if it's an error,
otherwise returns other. Because Dart evaluates operator operands
before calling the operator, this does not prevent other from being
created. Use andLazy when the fallback computation must be skipped.
Example:
final result = checkAuth(user) & validateData(data) & saveData(data);
Implementation
Result<T, E> operator &(Result<T, E> other) => and(other);