code: def test_struct_of_struct_copy():
      sr = cudf.Series([{"a": {"b": 1}}])
      assert_eq(sr, sr.copy())
  
imports: import numpy
  import pandas
  import pyarrow
  import pytest
  import cudf
  from cudf.core.dtypes import StructDtype
  from cudf.testing._utils import DATETIME_TYPES, TIMEDELTA_TYPES, assert_eq
label_desc: Use image node_id 2 for calling a global function with example usage: test_struct_of_struct_copy() without return types