InvocationTransaction: incorrect size calculation

[dauTT]

The following invocation transaction has size 219:

public void Test()
        {
            // taken from mainnet c4bb9b638da2e5f4a88ffcc4cb1d4f6693e7f19b7f78d242068254a6c77721f9
            // https://neoscan.io/transaction/C4BB9B638DA2E5F4A88FFCC4CB1D4F6693E7F19B7F78D242068254A6C77721F9

            String s = "d1015904802b530b14d5a682e81b8a840cc44b3b360cbd0f1ee6f50efd14235a717ed7ed18a43de47499c3d05b8d4a4bcf3a53c1087472616e7366657267fb1c540417067c270dee32f21023aa8b9b71abcef166fc47646b02d3f92300000000000000000120235a717ed7ed18a43de47499c3d05b8d4a4bcf3a0000014140b9234cad658c4d512bca453908a0df1c2beda49c544ec735bb492b81b4d0974ac8d66046061b3d0ce823e27c71fef1ee6a8f2fa369198ac74acedd045901d7222321030ab39b99d8675cd9bd90aaec37cba964297cc817078d33e508ab11f1d245c068ac";
            InvocationTransaction tx = (InvocationTransaction)Transaction.DeserializeFrom(s.HexToBytes());

            System.Console.WriteLine(tx.Size); // 219
            System.Console.WriteLine(tx.Version); // 1

        }

219 breaks down as follow:

//Size invocation transaction = Size base transaction + Size Script  
public override int Size => base.Size + Script.GetVarSize();  

//Size base transaction
public virtual int Size => sizeof(TransactionType) + sizeof(byte) + Attributes.GetVarSize() + Inputs.GetVarSize() + Outputs.GetVarSize() + Witnesses.GetVarSize();

Size invocation link
Size base transaction link

Looking at the serialization method of the invocation transactions:
https://github.com/CityOfZion/neo-python/blob/master/neo/Core/TX/InvocationTransaction.py#L74

we believe that 8 bytes should be added to the size calculation of the invocation transaction wheneve version >=1. In summary for the above transaction we woul expect it to have size
227 = 219+8
(ref: neo-go #185)