diff --git a/file_handler.py b/file_handler.py
index b54876d..ff88b1e 100644
--- a/file_handler.py
+++ b/file_handler.py
@@ -1,6 +1,6 @@
 import os
 import nixio as nix
-from nixio.pycore.util.util import check_entity_type
+from enum import Enum
 
 
 class ItemDescriptor():
@@ -15,6 +15,19 @@ class ItemDescriptor():
         self.entity_type = entity_type
         
     
+class NodeType(Enum):
+     Root = "root"
+     Section = "section"
+     Block = "block"
+     DataArray = "data_array"
+     DataFrame = "data_frame"
+     Property = "property"
+     Dimension = "dimension"
+     Source = "source"
+     Tag = "tag"
+     MultiTag = "multi_tag"
+     
+
 class Singleton(type):
     _instances = {}
     def __call__(cls, *args, **kwargs):
diff --git a/tree_model.py b/tree_model.py
index b6543a5..ed42754 100644
--- a/tree_model.py
+++ b/tree_model.py
@@ -7,14 +7,7 @@ from IPython import embed
 
 column_names = ['Name', 'Type', 'ID', 'Value', 'Description']
 
-class NodeType(Enum):
-     Root = "root"
-     Section = "section"
-     Block = "block"
-     DataArray = "data_array"
-     Property = "property"
-     Dimension = "dimension"
-     Tag = "tag"
+
 
 
 class NixTreeItem():