diff --git a/yapf/yapflib/reformatter.py b/yapf/yapflib/reformatter.py
index 7ed7a62..299fef8 100644
--- a/yapf/yapflib/reformatter.py
+++ b/yapf/yapflib/reformatter.py
@@ -439,7 +439,7 @@ def _IsClassOrDef(uwline):
   if uwline.first.value in {'class', 'def'}:
     return True
 
-  return (t.name for t in uwline.tokens[:2]) == ('async', 'def')
+  return [t.value for t in uwline.tokens[:2]] == ['async', 'def']
 
 
 def _CalculateNumberOfNewlines(first_token, indent_depth, prev_uwline,

Regression in formatting nested 'async def' functions
My style file has `blank_line_before_nested_class_or_def=False`.

Yapf 0.19.0 formats like:

```python
async def foo():
    async def bar():
        pass
```

Yapf 0.20.0 changes this to:

```python
async def foo():

    async def bar():
        pass
```

According to `git bisect`, this was introduced by 58e36945be8978deb7ab3ad3681f5feccb0405fc, which seems like it must be a bug, since that commit wasn't intended to change python 3 formatting at all.
diff --git a/yapftests/reformatter_python3_test.py b/yapftests/reformatter_python3_test.py
index c6a3e99..6ed1bbb 100644
--- a/yapftests/reformatter_python3_test.py
+++ b/yapftests/reformatter_python3_test.py
@@ -209,6 +209,17 @@ class TestsForPython3Code(yapf_test_helper.YAPFTest):
     uwlines = yapf_test_helper.ParseAndUnwrap(unformatted_code)
     self.assertCodeEqual(expected_formatted_code, reformatter.Reformat(uwlines))
 
+  def testAsyncFunctionsNested(self):
+    if sys.version_info[1] < 5:
+      return
+    code = textwrap.dedent("""\
+        async def outer():
+            async def inner():
+                pass
+        """)
+    uwlines = yapf_test_helper.ParseAndUnwrap(code)
+    self.assertCodeEqual(code, reformatter.Reformat(uwlines))
+
   def testKeepTypesIntact(self):
     if sys.version_info[1] < 5:
       return

pip install -e .
parse_log_pytest
pytest
pytest
3.6
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///opt/conda/conda-bld/attrs_1642510447205/work
certifi==2021.5.30
importlib-metadata @ file:///tmp/build/80754af9/importlib-metadata_1631916693255/work
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
more-itertools @ file:///tmp/build/80754af9/more-itertools_1637733554872/work
packaging @ file:///tmp/build/80754af9/packaging_1637314298585/work
pluggy @ file:///tmp/build/80754af9/pluggy_1615976315926/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pyparsing @ file:///tmp/build/80754af9/pyparsing_1635766073266/work
pytest==6.2.4
toml @ file:///tmp/build/80754af9/toml_1616166611790/work
typing_extensions @ file:///opt/conda/conda-bld/typing_extensions_1647553014482/work
-e git+https://github.com/google/yapf.git@c67685c0f4bf04dc2d34f8d615fa256181913788#egg=yapf
zipp @ file:///tmp/build/80754af9/zipp_1633618647012/work

name: yapf
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=21.4.0=pyhd3eb1b0_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - importlib-metadata=4.8.1=py36h06a4308_0
  - importlib_metadata=4.8.1=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - more-itertools=8.12.0=pyhd3eb1b0_0
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - packaging=21.3=pyhd3eb1b0_0
  - pip=21.2.2=py36h06a4308_0
  - pluggy=0.13.1=py36h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pyparsing=3.0.4=pyhd3eb1b0_0
  - pytest=6.2.4=py36h06a4308_2
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - toml=0.10.2=pyhd3eb1b0_0
  - typing_extensions=4.1.1=pyh06a4308_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.6.0=pyhd3eb1b0_0
  - zlib=1.2.13=h5eee18b_1
prefix: /opt/conda/envs/yapf

yapftests/reformatter_python3_test.py::TestsForPython3Code::testAsyncFunctionsNested
yapftests/reformatter_python3_test.py::TestsForPython3Code::testAnnotations yapftests/reformatter_python3_test.py::TestsForPython3Code::testAsyncFunctions yapftests/reformatter_python3_test.py::TestsForPython3Code::testAsyncWithPrecedingComment yapftests/reformatter_python3_test.py::TestsForPython3Code::testContinuationIndentWithAsync yapftests/reformatter_python3_test.py::TestsForPython3Code::testExecAsNonKeyword yapftests/reformatter_python3_test.py::TestsForPython3Code::testKeepTypesIntact yapftests/reformatter_python3_test.py::TestsForPython3Code::testKeywordOnlyArgSpecifier yapftests/reformatter_python3_test.py::TestsForPython3Code::testMatrixMultiplication yapftests/reformatter_python3_test.py::TestsForPython3Code::testNoSpacesAroundPowerOparator yapftests/reformatter_python3_test.py::TestsForPython3Code::testPEP448ParameterExpansion yapftests/reformatter_python3_test.py::TestsForPython3Code::testSpacesAroundDefaultOrNamedAssign yapftests/reformatter_python3_test.py::TestsForPython3Code::testSplittingArguments yapftests/reformatter_python3_test.py::TestsForPython3Code::testTypeHint yapftests/reformatter_python3_test.py::TestsForPython3Code::testTypedNames
yapf/yapflib/reformatter.py
yapf/yapflib/reformatter.py