code: def test_write_csv(pdf, hdfs, test_url):
      gdf = cudf.from_pandas(pdf)
      if test_url:
          hd_fpath = "hdfs://{}:{}{}/test_csv_writer.csv".format(
              host, port, basedir
          )
      else:
          hd_fpath = f"hdfs://{basedir}/test_csv_writer.csv"
  
      gdf.to_csv(hd_fpath, index=False)
  
      assert hdfs.exists(f"{basedir}/test_csv_writer.csv")
      with hdfs.open(f"{basedir}/test_csv_writer.csv", mode="rb") as f:
          got = pd.read_csv(f, dtype=dict(pdf.dtypes))
      assert_eq(pdf, got)
  
imports: import os
  from io import BytesIO
  import fastavro
  import numpy
  import pandas
  import pyarrow
  import pytest
  import cudf
  from cudf.testing._utils import assert_eq
label_desc: Use image node_id 4 for calling a global function with example usage: test_write_csv(pdf, hdfs, test_url) without return types