code: def test_astype_no_copy():
      arr = DummyArray(np.array([1, 2, 3], dtype=np.int64))
      result = arr.astype(arr.dtype, copy=False)
  
      assert arr is result
  
      result = arr.astype(arr.dtype)
      assert arr is not result
  
imports: import numpy
  import pytest
  from pandas.core.dtypes import dtypes
  from pandas.core.dtypes.common import is_extension_array_dtype
  import pandas
  import pandas._testing
  from pandas.core.arrays import ExtensionArray
label_desc: Use image node_id 2 for calling a global function with example usage: test_astype_no_copy() without return types