code: def dates():
      """pytest fixture"""
      start = datetime.datetime(2011, 1, 1)
      end = datetime.datetime(2012, 1, 1)
      rng = pd.date_range(start, end, freq="BM")
      return pd.DataFrame(
          {"numbers": np.random.randn(len(rng))}, index=rng
      )
  
imports: import datetime
  import re
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 1 for calling a global function with example usage: dates() and returns: pd