How to retrieve a list of document names linked to a given index in apache chemistry opencmis

Question

I was trying to retrieve a list of document names linked to a given index id (in my example "index-80") with the code below:

Note: The code below uses .Net but I can use java too.

IObjectId id = session.CreateObjectId("index-80");
IFolder indexFolder = session.GetObject(id) as IFolder;
foreach (ICmisObject cmisObject in indexFolder.GetChildren())
{
   Console.WriteLine(cmisObject.Name);
}

The issue is, the code will return only children indexes ("index-80" is parent of a couple of nested indexes in our CMIS repository) but it won't return documents linked to it.

After a bit of reading, it seems that documents are children of the ROOTFOLDER, but not of an indexentry. That will explain why the code above won't work.

How can I retrieve all document names linked to a given index in apache chemistry opencmis?