[Feature Request] Fork-Join about pipeline HOT 2 CLOSED

$pipeline = (new PipelineBuilder)
    ->pipe(new TimeTwoStage)
    ->fork(function($payload) {
            if($payload < 0) return "-";
            if($payload >= 0) return "+";
        })
        ->disjoin("-", $negativeNumberProcessingPipeline)
        ->disjoin("+", $positiveNumberOrZeroProcessingPipeline)
        ->join()
    ->pipe(new DivideByFiveStage)
    ->build();

use PhpFp\Either\Either;

$pipeline = new Pipeline();
$pipeline = $pipeline->pipe(function (Either $a) {
    return $a->chain(function ($x) {
        return $x * 2;
    };
});

$output = $pipeline->process(Either::of(2))->either(
    function ($left) {
        return 'failed';
    },
    function ($right) {
        return $right;
    }
);

assert($output === 4);