add read_data_type_definition() to Node class

asyncua/common/node.py

@@ -150,7 +150,15 @@ class Node:
         result = await self.read_attribute(ua.AttributeIds.NodeClass)
         return result.Value.Value
 
-    async def get_description(self):
+    async def read_data_type_definition(self):
+        """
+        get node class attribute of node
+        """
+        result = await self.read_attribute(ua.AttributeIds.DataTypeDefinition)
+        return result.Value.Value
+
+
+    async def read_description(self):
         """
         get description attribute class of node
         """
@@ -259,7 +267,7 @@ class Node:
         Set an attribute of a node
         attributeid is a member of ua.AttributeIds
         datavalue is a ua.DataValue object
-        indexrange is a NumericRange (a string; e.g. "1" or "1:3".  
+        indexrange is a NumericRange (a string; e.g. "1" or "1:3".
             See https://reference.opcfoundation.org/v104/Core/docs/Part4/7.22/)
         """
         attr = ua.WriteValue()