code: def test_iter(simple_data):
      """
      Test that iterating over the CA
      yields column names.
      """
      ca = ColumnAccessor(simple_data)
      for expect_key, got_key in zip(simple_data, ca):
          assert expect_key == got_key
  
imports: import pandas
  import pytest
  import cudf
  from cudf.core.column_accessor import ColumnAccessor
  from cudf.testing._utils import assert_eq
label_desc: Use image node_id 8 for calling a global function with example usage: test_iter(simple_data) without return types