Validator/Constraints/ChoiceValidator.php
public function validate($value, Constraint $constraint)
    {
        if ($value instanceof \Traversable) {
            $value = iterator_to_array($value);
        }

        parent::validate($value, $constraint);
    }
public function validate($value, Constraint $constraint)
    {
        if ($value instanceof \Traversable) {
            $value = iterator_to_array($value);
        }

        parent::validate($value, $constraint);
    }
{@inheritdoc}