Connector/IdentityService/IdentityService.php
public function isMappedIdentity($objectIdentifier, $objectType, $adapterName)
    {
        $identities = $this->findBy([
            'objectIdentifier' => $objectIdentifier,
            'objectType' => $objectType,
        ]);

        $otherIdentities = array_filter($identities, function (Identity $identity) use ($adapterName) {
            return $identity->getAdapterName() !== $adapterName;
        });

        if (empty($otherIdentities)) {
            return false;
        }

        return true;
    }
public function isMappedIdentity($objectIdentifier, $objectType, $adapterName)
    {
        $identities = $this->findBy([
            'objectIdentifier' => $objectIdentifier,
            'objectType' => $objectType,
        ]);

        $otherIdentities = array_filter($identities, function (Identity $identity) use ($adapterName) {
            return $identity->getAdapterName() !== $adapterName;
        });

        if (empty($otherIdentities)) {
            return false;
        }

        return true;
    }
{@inheritdoc}