public function testEither()
{
$addOne = function ($x) {
return $x + 1;
};
$takeOne = function ($x) {
return $x - 1;
};
$a = new Right(2);
$b = new Left(2);
$this->assertEquals($a->either($addOne, $takeOne), 1, 'Eithers a Right.');
$this->assertEquals($b->either($addOne, $takeOne), 3, 'Eithers a Left.');
}
