modified jupyter helper for collaboration >=2.x

src/cristallina/jupyter_helper.py

@@ -4,14 +4,28 @@ To use:
 
 jupyter lab --YDocExtension.ystore_class=cristallina.jupyter_helper.MySQLiteYStore
 
+In 2.0.x this is replaced by:
+# The Store class used for storing Y updates (default: SQLiteYStore).
+jupyter lab --YDocExtension.ystore_class=jupyter_collaboration.stores.FileYStore
+
 This should work on the local consoles and also on RA (yet untested).
 """
 
+from packaging.version import Version
 import random
 
-from ypy_websocket.ystore import SQLiteYStore
+import jupyter_collaboration
+
+if Version(jupyter_collaboration.__version__) < Version("1.9"):
+    from ypy_websocket.ystore import SQLiteYStore
+   
+else:   
+    # approach for >=2.0
+    from jupyter_collaboration.stores import SQLiteYStore
 
 class MySQLiteYStore(SQLiteYStore):
+    """
+     Custom SQL location for jupyter collaboration to avoid NFS locking issues. 
+    """
     suffix = random.randint(0, 1E9)
     db_path = f"/tmp/ystore_{suffix}.db"
-