public async Task ShouldReturnTransactions()
{
ulong block = 9148873;
var ethereumService = new EthereumService(Configuration, Mapper);
var txns = await ethereumService.GetTxns(block).ConfigureAwait(false);
txns.Should <TransactionVewModel>();
txns.Count().Should().BeGreaterOrEqualTo(0);
// You can add more test conditions here..........
}