code: def input(self):
      return self._input
  
imports: from collections import OrderedDict
  import numpy
  import pandas
  from ...None import opcodes
  from ...core import ENTITY_TYPE, recursive_tile
  from ...serialization.serializables import KeyField, AnyField, StringField, DataTypeField, BoolField, Int32Field
  from ...tensor.core import TENSOR_TYPE, TENSOR_CHUNK_TYPE
  from ...tensor.datasource import empty, tensor, from_series, from_dataframe
  from ...tensor.statistics.quantile import quantile
  from ..operands import DataFrameOperand, DataFrameOperandMixin
  from ..core import DATAFRAME_TYPE
  from ..datasource.from_tensor import series_from_tensor, dataframe_from_tensor
  from ..initializer import DataFrame
  from ..utils import parse_index, build_empty_df, find_common_type, validate_axis
label_desc: Use image node_id 2 for calling the DataFrameQuantile obj's underlying member method code with example usage: obj.input() and returns: self