TIMESUM syntax error

Hi everyone ! 

I am currently doing the Level 2 Model Builder, Sprint 1, and I am stuck at step 1.5.7

Basically, I need to feed a boolean Line Item called "Has Data?", which is on the SKU ; Account dimensions from a numeric Line Item called Volumes, which is on SKU ; Account ; FY19 dimension. Therefore, I need to aggregate the data on the time dimension, using a ANY aggregation method to retrieve a boolean value. 

Here is how I try to feed "Has Data?":

TIMESUM('DAT03 Historic Volumes'.Volumes , , ,ANY)

or 

TIMESUM('DAT03 Historic Volumes'.Volumes, From, To, ANY)

and even

TIMESUM('DAT03 Historic Volumes'.Volumes [,] [,] [,ANY])

None of these worked, I'm stuck...

Here is what I found on Anapedia : 

TIMESUM(Line item to aggregate [, Start period] [, End period] [, Aggregation method])

Start Period & End Period are non mandatory values according to Anapedia. However, missing intermediate parameters are not permitted. I'm not sure what's that suppose to mean... 

Thanks in advance for your kind help ! 

Benoît