src/Model/Attribute/Accessor/Owner.php
public function setOwner(?string $owner)
    {
        if (null !== $owner) {
            if (!preg_match('/^[a-z]+$/i', $owner)) {
                throw new DomainException('Owner is not valid.');
            }
        }

        $this->owner = $owner;

        return $this;
    }
public function setOwner(?string $owner)
    {
        if (null !== $owner) {
            if (!preg_match('/^[a-z]+$/i', $owner)) {
                throw new DomainException('Owner is not valid.');
            }
        }

        $this->owner = $owner;

        return $this;
    }
Set owner

@param string $owner
@return object
@throws \DomainException