code: def test_concat_all_nulls(values):
      pa = pd.Series(values)
      pb = pd.Series([None])
      ps = pd.concat([pa, pb])
  
      ga = gd.Series(values)
      gb = gd.Series([None])
      gs = gd.concat([ga, gb])
  
      assert_eq(
          ps,
          gs,
          check_dtype=False,
          check_categorical=False,
          check_index_type=True,
      )
  
imports: from decimal import Decimal
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf.api.types import is_categorical_dtype
  from cudf.core._compat import PANDAS_GE_150, PANDAS_LT_140
  from cudf.core.dtypes import Decimal32Dtype, Decimal64Dtype, Decimal128Dtype
  from cudf.testing._utils import assert_eq, assert_exceptions_equal
label_desc: Use image node_id 3 for calling a global function with example usage: test_concat_all_nulls(values) without return types