code: def test_ragged_count(self, ragged):
      df = ragged
      result = df.rolling(window="1s", min_periods=1).count()
      expected = df.copy()
      expected["B"] = [1.0, 1, 1, 1, 1]
      tm.assert_frame_equal(result, expected)
  
      df = ragged
      result = df.rolling(window="1s").count()
      tm.assert_frame_equal(result, expected)
  
      result = df.rolling(window="2s", min_periods=1).count()
      expected = df.copy()
      expected["B"] = [1.0, 1, 2, 1, 2]
      tm.assert_frame_equal(result, expected)
  
      result = df.rolling(window="2s", min_periods=2).count()
      expected = df.copy()
      expected["B"] = [np.nan, np.nan, 2, np.nan, 2]
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  import pandas.util._test_decorators
  from pandas import DataFrame, DatetimeIndex, Index, MultiIndex, NaT, Series, Timestamp, date_range
  import pandas._testing
  from pandas.tseries import offsets
label_desc: Use image node_id 22 for calling the TestRollingTS obj's underlying member method code with example usage: obj.test_ragged_count(ragged) without return types