I am getting all nodes even with setting a value for "threshold" [unionFind]

I am trying to make clusters that has my nodes which collaborated together :
So I started first by regrouping them :

MATCH (at1:Attributaire18)<-[r:ASSIGNED_TO18]-(c:Contrat18)-[x:ASSIGNED_TO18]->(at2:Attributaire18)
MERGE (at1)-[s:CollaborateWith18]-(at2)

And then I set weight for the relations by running this query :

match (a:Attributaire18)--(h:Attributaire18) 
with a, count(h) as AttributaireCount 
match (a)-[r]-() 
set r.weight = AttributaireCount

And finally to make clusters that contains "Attributaire18" which collaborated together , I ran this query , and I set "threshold=2.0" to exclude nodes which have less then 2 as weight of their relations from clusters :

CALL algo.unionFind('Attributaire18', 'CollaborateWith18', {write:true, partitionProperty:"clusterId",weightProperty:'weight', defaultValue:0.0, threshold:2.0, concurrency: 1})
YIELD nodes, setCount, loadMillis, computeMillis, writeMillis;  

But I am still seeing all nodes ! I need help please !