public class Block
{
    [JsonProperty(Order = 1, NullValueHandling = NullValueHandling.Include, PropertyName = "index")]
    public int Index { get; set; }

    [JsonProperty(Order = 2, NullValueHandling = NullValueHandling.Include, PropertyName = "timestamp")]
    public int Timestamp { get; set; } = (int)DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;

    [JsonProperty(Order = 3, NullValueHandling = NullValueHandling.Include, PropertyName = "transactions")]
    public IList<Transaction> Transactions { get; set; }

    [JsonProperty(Order = 4, NullValueHandling = NullValueHandling.Include, PropertyName = "proof")]
    public int Proof { get; set; }

    [JsonProperty(Order = 5, NullValueHandling = NullValueHandling.Include, PropertyName = "previous_hash")]
    public string PreviousHash { get; set; }
}