code: def test_dtypes(arr):
      table = pa.table([arr], names=["a"])
      df = table.__dataframe__()
  
      null_count = df.get_column(0).null_count
      assert null_count == arr.null_count
      assert isinstance(null_count, int)
      assert df.get_column(0).size() == 3
      assert df.get_column(0).offset == 0
  
file_path: arrow/python/pyarrow/tests/interchange/test_interchange_spec.py
imports: import ctypes
  import hypothesis
  import hypothesis.strategies
  import numpy
  import pyarrow
  import pyarrow.tests.strategies
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: test_dtypes(arr) without return types