code: def _get_empty_dtype(join_units: Sequence[JoinUnit]) -> DtypeObj:
      """
      Return dtype and N/A values to use when concatenating specified units.
  
      Returned N/A value may be None which means there was no casting involved.
  
      Returns
      -------
      dtype
      """
      if len(join_units) == 1:
          blk = join_units[0].block
          return blk.dtype
  
      if _is_uniform_reindex(join_units):
          empty_dtype = join_units[0].block.dtype
          return empty_dtype
  
      has_none_blocks = any(
          unit.block.dtype.kind == "V" for unit in join_units
      )
  
      dtypes = [unit.dtype for unit in join_units if not unit.is_na]
      if not len(dtypes):
          dtypes = [
              unit.dtype
              for unit in join_units
              if unit.block.dtype.kind != "V"
          ]
  
      dtype = find_common_type(dtypes)
      if has_none_blocks:
          dtype = ensure_dtype_can_hold_na(dtype)
      return dtype
  
imports: from __future__ import annotations
  import copy
  import itertools
  from typing import TYPE_CHECKING, Sequence, cast
  import numpy
  from pandas._libs import NaT, internals
  from pandas._libs.missing import NA
  from pandas._typing import ArrayLike, AxisInt, DtypeObj, Manager, Shape
  from pandas.util._decorators import cache_readonly
  from pandas.core.dtypes.astype import astype_array
  from pandas.core.dtypes.cast import ensure_dtype_can_hold_na, find_common_type, np_find_common_type
  from pandas.core.dtypes.common import is_1d_only_ea_dtype, is_dtype_equal, is_scalar, needs_i8_conversion
  from pandas.core.dtypes.concat import concat_compat
  from pandas.core.dtypes.dtypes import DatetimeTZDtype, ExtensionDtype
  from pandas.core.dtypes.missing import is_valid_na_for_dtype, isna, isna_all
  import pandas.core.algorithms
  from pandas.core.arrays import DatetimeArray, ExtensionArray
  from pandas.core.arrays.sparse import SparseDtype
  from pandas.core.construction import ensure_wrapped_if_datetimelike
  from pandas.core.internals.array_manager import ArrayManager, NullArrayProxy
  from pandas.core.internals.blocks import ensure_block_shape, new_block_2d
  from pandas.core.internals.managers import BlockManager
label_desc: Use image node_id 9 for calling a global function with example usage: _get_empty_dtype(join_units) and returns: dtype, blk, empty_dtype