flatMapTuple2<L, R, R2>  function 
 
        
Either<L, dynamic>  Function(Either<L, R>  either)
flatMapTuple2<L, R, R2>( 
    
- Either<L, R2> f(- R value
 
A variant of flatMap that appends the result to a tuple.
Implementation
Either<L, Tuple2<R, R2>> Function(Either<L, R> either) flatMapTuple2<L, R, R2>(
  Either<L, R2> Function(R value) f,
) =>
    fold(left, (r) => f(r).p(map((r2) => tuple2(r, r2))));