code: def test_query_env_changing():
      df = DataFrame()
      df["a"] = aa = np.arange(100)
      expr = "a < @c"
      # first attempt
      c = 10
      got = df.query(expr)
      np.testing.assert_array_equal(aa[aa < c], got["a"].to_numpy())
      # change env
      c = 50
      got = df.query(expr)
      np.testing.assert_array_equal(aa[aa < c], got["a"].to_numpy())
  
imports: import datetime
  import inspect
  from itertools import product
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf import DataFrame
  from cudf.testing._utils import assert_eq
  from cudf.utils import queryutils
label_desc: Use image node_id 4 for calling a global function with example usage: test_query_env_changing() without return types