Adldap\Laravel\Traits\AuthenticatesUsers::retrieveByCredentials PHP Method

    public function retrieveByCredentials(array $credentials = [])
    {
        $username = $this->getUsernameFromCredentials($credentials);
        // Make sure we're connected to our LDAP server before we run any operations.
        if ($username && $this->isConnected()) {
            // Due to having the ability of choosing which attribute we login users
            // with, we actually need to retrieve the user from our LDAP server
            // before hand so we can retrieve these attributes.
            $user = $this->newAdldapUserQuery()->where([$this->getUsernameValue() => $username])->first();
            if ($user instanceof User) {
                // Perform operations on the discovered user.
                $this->handleDiscoveredUserWithCredentials($user);
                return $user;
            }
        }
    }