$team = Team::create(['name'=> 'My team', 'owner_id' => $user->id]));

$user->attachTeam($team);

// If user already have any other current team, we have to separately switch team
$user->switchTeam($team);

// If this is first team of user, user's current team will be this new team
$team = $user->createOwnedTeam(['name' => 'My awesome team']);

// If the user has teams, we want the user to switch to this new team, pass second parameter true to this method.
$team = $user->createOwnedTeam(['name' => 'My awesome team'], true);