docstr: Test deprecated_arg decorator raises exception with no versions set.
docstr_tok: ["Test","deprecated_arg","decorator","raises","exception","with","no","versions","set","."]
code: def test_arg_except1(self):
      """Test deprecated_arg decorator raises exception with no versions set."""
  
      @deprecated_arg("b", version_val=self.test_version)
      def afoo3(a, b=None):
          pass
  
      self.assertRaises(DeprecatedError, lambda: afoo3(1, b=2))
  
imports: from __future__ import annotations
  import unittest
  import warnings
  from monai.utils import DeprecatedError, deprecated, deprecated_arg, deprecated_arg_default
label_desc: Use image node_id 14 for calling the TestDeprecated obj's underlying member method code with example usage: obj.test_arg_except1() without return types