code: def _tile_series_index(cls, op):
      in_series = op.inputs[0]
      out = op.outputs[0]
  
      unique_chunk = None
      if op.dtype_values == "category" and isinstance(
          op.dtype_values, str
      ):
          unique_chunk = (
              yield from recursive_tile(sort(in_series.unique()))
          ).chunks[0]
  
      chunks = []
      for c in in_series.chunks:
          chunk_op = op.copy().reset_key()
          params = c.params.copy()
          params["dtype"] = out.dtype
          if unique_chunk is not None:
              chunk_op._category_cols = [in_series.name]
              new_chunk = chunk_op.new_chunk(
                  [c, unique_chunk], **params
              )
          else:
              new_chunk = chunk_op.new_chunk([c], **params)
          chunks.append(new_chunk)
  
      new_op = op.copy()
      return new_op.new_tileables(
          op.inputs,
          nsplits=in_series.nsplits,
          chunks=chunks,
          **out.params.copy(),
      )
  
imports: import numpy
  import pandas
  from pandas.api.types import CategoricalDtype
  from ...None import opcodes
  from ...core import recursive_tile
  from ...serialization.serializables import AnyField, StringField, ListField
  from ...tensor.base import sort
  from ...utils import pd_release_version
  from ..core import DATAFRAME_TYPE, SERIES_TYPE
  from ..operands import DataFrameOperand, DataFrameOperandMixin
  from ..utils import build_empty_df, build_empty_series, parse_index
label_desc: Use image node_id 6 for calling the DataFrameAstype obj's underlying member method code with example usage: obj._tile_series_index(cls, op) and returns: new_op