You should not install this until you are told.
I don't know how to obtain the damageSourceId from damage did by local player. So the DamageHistoryStruct which local player is the attacker, has eDamageSourceId.damagedef_unknown as damageSourceId.
DamageHistoryStruct function GetLastDamageHistoryByAttackerAndDamageSourceId( entity victim, entity attacker, int damageSourceId)
DamageHistoryStruct function GetLastDamageHistoryByDamageSourceId( entity victim, int damageSourceId )
DamageHistoryStruct function GetLastDamageHistoryByAttacker( entity victim, entity attacker )
array<DamageHistoryStruct> function GetDamageHistoryByAttacker( entity player, entity attacker, float time = 0 )
//string function DamageSourceIDToString( damageHistory.damageSourceId )
array<DamageHistoryStruct> function GetDamageHistoryByDamageSourceId( entity player, int damageSourceId, float time = 0 )
array<DamageHistoryStruct> function GetDamageHistoryByAttackerAndDamageSourceId( entity player, entity attacker, int damageSourceId, float time = 0 )
array<DamageHistoryStruct> function GetDamageHistoryIncludeLocalClientPlayer( )
bool function WasRecentlyHitByEntityAndDamageSourceId( entity player, entity attacker, int damageSourceId, float hitTime )