Need help with Siege trait triggers

If I want to add a trigger that gives a general a trait when fighting siege battles, how do I do? I've done some modding to traits and triggers, so I know how to add a trigger, it's just the siege-part I don't know how to do.

Like this (but I guess I need to add another condition, but I don't know what?):
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Trigger goodsiegeattacker
WhenToTest PostBattle

Condition WasAttacker
and IsGeneral
and WonBattle
and I_ConflictType Normal


Affects GoodSiegeAttacker 1 Chance 50

;------------------------------------------

Code:

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;------------------------------------------
Trigger goodsiegeattacker
WhenToTest PostBattle

Condition WasAttacker
        and IsGeneral
        and WonBattle
        and I_ConflictType Siege

Affects GoodSiegeAttacker 1 Chance 50

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This thread (Events, Conditions, and Commands) lists the I_ConflictTypes:

https://forums.totalwar.org/vb/showthread.php?t=43121


Here's the relevant section:

Quote:

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Identifier: I_ConflictType
Trigger requirements:
Parameters: conflict type (SuccessfulAmbush, FailedAmbush, SuccessfulNightRaid, FailedNightRaid, Normal, Siege, SallyBesieger, Naval, Withdraw)
Sample use: I_ConflictType SuccessfulNightRaid
Description: Test the type of conflict (ambush, siege &c.)
Battle or Strat: Either
Class: BATTLE_CONFLICT_TYPE
Implemented: Yes
Author: Lee

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