[storm] BoundReferenceSet limiting results

[Михаил]

Hello there!

I have a table like

class Servers(Storm):
    __storm_table__ = 'servers'
    id = Int(primary = True)
    ip = Int()
    hostname = Unicode()
    path = Unicode()
    comment = Unicode()
    wait = Int()
    disk_available = Int()
    disk_used = Int()
    priority = Float()
    files = ReferenceSet(id, 'Files.server_id')

How I can limit result of BoundReferenceSet object (Servers.files)? I tried

s = store.get(Servers, 1)
s.files[0:10]

but got the error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'BoundReferenceSet' object is unsubscriptable