code: def unstack(
      obj: Series, level, fill_value=..., sort: bool = ...
  ) -> DataFrame:
      ...
  
imports: from __future__ import annotations
  import itertools
  from typing import TYPE_CHECKING, cast, overload
  import warnings
  import numpy
  import pandas._libs.reshape
  from pandas.errors import PerformanceWarning
  from pandas.util._decorators import cache_readonly
  from pandas.util._exceptions import find_stack_level
  from pandas.core.dtypes.cast import find_common_type, maybe_promote
  from pandas.core.dtypes.common import ensure_platform_int, is_1d_only_ea_dtype, is_integer, needs_i8_conversion
  from pandas.core.dtypes.dtypes import ExtensionDtype
  from pandas.core.dtypes.missing import notna
  import pandas.core.algorithms
  from pandas.core.algorithms import factorize, unique
  from pandas.core.arrays.categorical import factorize_from_iterable
  from pandas.core.construction import ensure_wrapped_if_datetimelike
  from pandas.core.frame import DataFrame
  from pandas.core.indexes.api import Index, MultiIndex, RangeIndex
  from pandas.core.reshape.concat import concat
  from pandas.core.series import Series
  from pandas.core.sorting import compress_group_index, decons_obs_group_ids, get_compressed_ids, get_group_index, get_group_index_sorter
label_desc: Use image node_id 2 for calling a global function with example usage: unstack(obj, level, fill_value, sort) without return types