code: def test_groupby_rolling_center_on(self):
      # GH 37141
      df = DataFrame(
          data={
              "Date": date_range("2020-01-01", "2020-01-10"),
              "gb": ["group_1"] * 6 + ["group_2"] * 4,
              "value": range(10),
          }
      )
      result = (
          df.groupby("gb")
          .rolling(6, on="Date", center=True, min_periods=1)
          .value.mean()
      )
      mi = MultiIndex.from_arrays(
          [df["gb"], df["Date"]], names=["gb", "Date"]
      )
      expected = Series(
          [1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 7.0, 7.5, 7.5, 7.5],
          name="value",
          index=mi,
      )
      tm.assert_series_equal(result, expected)
  
imports: import numpy
  import pytest
  from pandas import DataFrame, DatetimeIndex, Index, MultiIndex, Series, Timestamp, date_range, to_datetime
  import pandas._testing
  from pandas.api.indexers import BaseIndexer
  from pandas.core.groupby.groupby import get_groupby
label_desc: Use image node_id 15 for calling the TestRolling obj's underlying member method code with example usage: obj.test_groupby_rolling_center_on() without return types