code: def func(self):
      return self._func
  
imports: import numpy
  import pandas
  from ....None import opcodes
  from ....core import recursive_tile
  from ....serialization.serializables import FieldTypes, AnyField, Int64Field, BoolField, StringField, Int32Field, KeyField, TupleField, DictField, ListField
  from ....utils import lazy_import, has_unknown_shape, pd_release_version, calc_nsplits
  from ...operands import DataFrameOperand, DataFrameOperandMixin
  from ...core import DATAFRAME_TYPE
  from ...utils import build_empty_df, build_empty_series, parse_index
label_desc: Use image node_id 10 for calling the DataFrameRollingAgg obj's underlying member method code with example usage: obj.func() and returns: self