How to use the ccxt.BaseError function in ccxt

async getTicker(pair, ccxtParams)
{
    let ccxtPair = this._toCcxtPair(pair);
    let data;
    try
    {
        data = await this.ccxt.fetchTicker(ccxtPair, ccxtParams);
    }
    catch (e)
    {
        if (e instanceof ccxt.BaseError)
        {
            throw new CcxtErrors.BaseError(e, undefined, undefined, undefined);
        }
        throw e;
    }
    return {ccxt:data,custom:this.formatTicker(pair, data)};
}