diff --git a/tools/python/jwutils/ArgsContainer.py b/tools/python/jwutils/ArgsContainer.py
index a0aa7f5..5019701 100644
--- a/tools/python/jwutils/ArgsContainer.py
+++ b/tools/python/jwutils/ArgsContainer.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 
+import argparse
+
 from collections import OrderedDict
 
 from jwutils.log import *
@@ -60,3 +62,18 @@ class ArgsContainer: # export
             except:
                 pass
             slog(prio, f'{name}: {val}', caller=caller)
+
+def add_argument(p: argparse.ArgumentParser|ArgsContainer, name: str, *args, **kwargs): # export
+
+    key = name.strip('--').replace('-', '_')
+    if isinstance(p, ArgsContainer):
+        if key in p.keys():
+            return
+    elif isinstance(p, argparse.ArgumentParser):
+        for action in p._actions:
+            if key == action.dest:
+                return
+    else:
+        raise Exception('Unknown type {type(p)} of {p} passed to add_argument()')
+
+    p.add_argument(name, *args, **kwargs)