code: def test_Float64_conversion():
      # GH#40729
      testseries = pd.Series(["1", "2", "3", "4"], dtype="object")
      result = testseries.astype(pd.Float64Dtype())
  
      expected = pd.Series(
          [1.0, 2.0, 3.0, 4.0], dtype=pd.Float64Dtype()
      )
  
      tm.assert_series_equal(result, expected)
  
file_path: pandas/pandas/tests/arrays/floating/test_astype.py
imports: import numpy
  import pytest
  import pandas
  import pandas._testing
label_desc: Use image node_id 8 for calling a global function with example usage: test_Float64_conversion() without return types