Suport nullable List of nullables.

Author: cancan101

graphqldb/adapter.py

@@ -415,17 +415,24 @@ def __init__(
             list_type = cast(TypeInfo, list_type)
 
             item_container_type = list_type["ofType"]
-            if item_container_type is None:
+            item_container_name = list_type["name"]
+            if item_container_type is not None:
+                # TODO(cancan101): put this info into type system
+                item_container_type = cast(TypeInfo, item_container_type)
+            elif item_container_name is not None:
+                item_container_type = list_type
+            else:
                 raise ValueError("Unable to resolve item_container_type")
 
-            # TODO(cancan101): put this info into type system
-            item_container_type = cast(TypeInfo, item_container_type)
-
             node_type = item_container_type["ofType"]
-            if node_type is None:
+            node_name = item_container_type["name"]
+            if node_type is not None:
+                node_type_name = node_type["name"]
+            elif node_name is not None:
+                node_type_name = node_name
+            else:
                 raise ValueError("Unable to resolve node_type")
 
-            node_type_name = node_type["name"]
             if node_type_name is None:
                 raise ValueError("Unable to resolve node_type_name")