Gremlin group by and update

I have query that calculates number of inbound edges:

 g.V().in().groupCount().unfold()

How can I update property f.e. "inCount" of each Vertexes with number of inbound edges?

>Solution :

The property() step can take a Traversal as an argument for the value so:

gremlin> g.V().property('inCount', inE().count())
==>v[1]
==>v[2]
==>v[3]
==>v[4]
==>v[5]
==>v[6]
gremlin> g.V().elementMap()
==>[id:1,label:person,name:marko,inCount:0,age:29]
==>[id:2,label:person,name:vadas,inCount:1,age:27]
==>[id:3,label:software,name:lop,lang:java,inCount:3]
==>[id:4,label:person,name:josh,inCount:1,age:32]
==>[id:5,label:software,name:ripple,lang:java,inCount:1]
==>[id:6,label:person,name:peter,inCount:0,age:35]