code: def fill_value(self):
      return self._fill_value
  
imports: import numpy
  import pandas
  from ...None import opcodes
  from ...core import ENTITY_TYPE, recursive_tile
  from ...core.operand import OperandStage
  from ...serialization.serializables import KeyField, AnyField, StringField, Int64Field, BoolField
  from ...tensor import tensor
  from ...utils import lazy_import, pd_release_version
  from ..core import Index, INDEX_TYPE
  from ..initializer import Index
  from ..operands import DataFrameOperand, DataFrameOperandMixin
  from ..utils import validate_axis_style_args, parse_index
  from .index_lib import DataFrameReindexHandler
label_desc: Use image node_id 8 for calling the DataFrameReindex obj's underlying member method code with example usage: obj.fill_value() and returns: self