function setNFTXVaultFactory(address newFactory) external virtual override onlyOwner {
  require(newFactory != address(0));
  nftxVaultFactory = INFTXVaultFactory(newFactory);
}
function setNFTXVaultFactory(address newFactory) external virtual override onlyOwner {
  require(nftxVaultFactory == address(0), "nftxVaultFactory is immutable");
  nftxVaultFactory = INFTXVaultFactory(newFactory);
}
