AdamWathan\EloquentOAuth\Authenticator::storeProviderIdentity PHP Method

    protected function storeProviderIdentity($user, $providerAlias, $details)
    {
        if ($this->identities->userExists($providerAlias, $details)) {
            $this->updateProviderIdentity($providerAlias, $details);
        } else {
            $this->addProviderIdentity($user, $providerAlias, $details);
        }
    }