function syncDeps(IRegistry _registry) public onlyGovernance {
    vusd = IERC20(_registry.vusd());
    marginAccount = _registry.marginAccount();
}
function syncDeps(IRegistry _registry) public onlyGovernance {
    uint _balance = balance();
    vusd = IERC20(_registry.vusd());
    require(balance() >= _balance);
    marginAccount = _registry.marginAccount();
}
