*/ interface AbTestInterface { public function getName(): string; public function getResult(); public function setResult(string $result): self; public function isValidVariation($variation): bool; public function addVariation(string $name, $value, int $probability = null): self; public function getVariation($variation); public function getResultValue(); public function setDuration(int $duration): self; public function getDuration(): int; public function run(): self; }