PHPStan\Reflection\Php\PhpMethodReflection::getReturnType PHP Method

    public function getReturnType() : Type
    {
        if ($this->returnType === null) {
            $this->returnType = TypehintHelper::decideType($this->reflection->getReturnType(), $this->phpDocReturnType, $this->declaringClass->getName());
        }
        return $this->returnType;
    }