void SetAsPreviousValue ( const [FNiagaraVariableBase](API\Plugins\Niagara\FNiagaraVariableBase) & Src, const [FVersionedNiagaraEmitter](API\Plugins\Niagara\FVersionedNiagaraEmitter) & InEmitter, [ENiagaraRendererSourceDataMode](API\Plugins\Niagara\ENiagaraRendererSourceDataMode) InSourceMode )