code: def test_null_dataframe(ncols):
      size = 20
      gdf = cudf.DataFrame()
      for idx, dtype in enumerate(dtype_categories):
          sr = cudf.Series(np.random.randint(0, 128, size)).astype(
              dtype
          )
          sr[np.random.choice([False, True], size=size)] = None
          gdf[dtype] = sr
      pdf = gdf.to_pandas()
      pd.options.display.max_columns = int(ncols)
      pdf_repr = (
          repr(pdf).replace("NaN", "<NA>").replace("None", "<NA>")
      )
      assert pdf_repr.split() == repr(gdf).split()
      pd.reset_option("display.max_columns")
  
imports: import textwrap
  import cupy
  import numpy
  import pandas
  import pytest
  from hypothesis import given, settings, strategies
  import cudf
  from cudf.testing import _utils
  from cudf.utils.dtypes import np_dtypes_to_pandas_dtypes
label_desc: Use image node_id 2 for calling a global function with example usage: test_null_dataframe(ncols) without return types