How to use the @0x/asset-swapper.BigNumber function in @0x/asset-swapper

export const assetDataForERC721TokenAddress = (tokenAddress: string, tokenId: string | number): string => {
    assert.isETHAddressHex('tokenAddress', tokenAddress);
    return assetDataEncoder.ERC721Token(tokenAddress, new BigNumber(tokenId)).getABIEncodedTransactionData();
};

let provider = supportedProvider;
    if (provider !== undefined) {
        provider = providerUtils.standardizeOrThrow(provider);
    }

    const bestProvider: ZeroExProvider = provider || providerFactory.getFallbackNoSigningProvider(chainId);

    const swapQuoterOptions = { chainId };

    const swapQuoter = _.isString(orderSource)
        ? SwapQuoter.getSwapQuoterForStandardRelayerAPIUrl(bestProvider, orderSource, swapQuoterOptions)
        : SwapQuoter.getSwapQuoterForProvidedOrders(bestProvider, orderSource, swapQuoterOptions);

    const wethAssetData = await swapQuoter.getEtherTokenAssetDataOrThrowAsync();
    const liquidity = await swapQuoter.getLiquidityForMakerTakerAssetDataPairAsync(wethAssetData, takerAssetData);
    return liquidity.makerAssetAvailableInBaseUnits.gt(new BigNumber(0));
};