code: def test_dtypes_defaultdict(all_parsers, default):
      # GH#41574
      data = """a,b
  1,2
  """
      dtype = defaultdict(lambda: default, a="int64")
      parser = all_parsers
      result = parser.read_csv(StringIO(data), dtype=dtype)
      expected = DataFrame({"a": [1], "b": 2.0})
      tm.assert_frame_equal(result, expected)
  
imports: from collections import defaultdict
  from io import StringIO
  import numpy
  import pytest
  from pandas.errors import ParserWarning
  import pandas
  from pandas import DataFrame, Timestamp
  import pandas._testing
  from pandas.core.arrays import ArrowStringArray, IntegerArray, StringArray
label_desc: Use image node_id 18 for calling a global function with example usage: test_dtypes_defaultdict(all_parsers, default) without return types