docstr: Test deprecated arg default, where the current version is less than `since` (no warning).
docstr_tok: ["Test","deprecated","arg","default",",","where","the","current","version","is","less","than","`","since","`","(","no","warning",")","."]
code: def test_deprecated_arg_default_version_less_than_since(self):
      """
      Test deprecated arg default, where the current version is less than `since` (no warning).
      """
  
      @deprecated_arg_default(
          "b",
          old_default="a",
          new_default="b",
          since=self.test_version,
          version_val=self.prev_version,
      )
      def foo(a, b="a"):
          return a, b
  
      with self.assertWarns(FutureWarning) as aw:
          self.assertEqual(foo("a"), ("a", "a"))
          self.assertEqual(foo("a", "a"), ("a", "a"))
          warnings.warn("fake warning", FutureWarning)
  
      self.assertEqual(aw.warning.args[0], "fake warning")
  
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 24 for calling the TestDeprecated obj's underlying member method code with example usage: obj.test_deprecated_arg_default_version_less_than_since() and returns: a,  b