public async Task <BalanceHistory[]> GetBalanceHistory(CurrencyCode currencyCode, int?count = null, int?before = null, int?after = null, CancellationToken cancellationToken = default) { var query = new Dictionary <string, object>() { { "currency_code", currencyCode.GetEnumMemberValue() } }; if (count != null) { query["count"] = count.Value; } if (before != null) { query["before"] = before.Value; } if (after != null) { query["after"] = after.Value; } return(await Get <BalanceHistory[]>(BalanceHistoryApiPath, query, cancellationToken : cancellationToken).ConfigureAwait(false)); }