src/Definition/Type/SetType.php
public function normalize($data)
    {
        if (!$data instanceof SetInterface) {
            throw new NormalizationException(
                'The value must be an instance of Innmind\Immutable\SetInterface'
            );
        }

        return $data->reduce(
            [],
            function(array $values, $value): array {
                $values[] = $this->inner->normalize($value);

                return $values;
            }
        );
    }
public function normalize($data)
    {
        if (!$data instanceof SetInterface) {
            throw new NormalizationException(
                'The value must be an instance of Innmind\Immutable\SetInterface'
            );
        }

        return $data->reduce(
            [],
            function(array $values, $value): array {
                $values[] = $this->inner->normalize($value);

                return $values;
            }
        );
    }
{@inheritdoc}