code: def get_indexer_non_unique(
      self, target: Index
  ) -> tuple[npt.NDArray[np.intp], npt.NDArray[np.intp]]:
      target = ensure_index(target)
  
      if not self._should_compare(
          target
      ) and not self._should_partial_index(target):
          # e.g. IntervalIndex with different closed or incompatible subtype
          #  -> no matches
          return self._get_indexer_non_comparable(
              target, None, unique=False
          )
  
      elif isinstance(target, IntervalIndex):
          if self.left.is_unique and self.right.is_unique:
              # fastpath available even if we don't have self._index_as_unique
              indexer = self._get_indexer_unique_sides(target)
              missing = (indexer == -1).nonzero()[0]
          else:
              return self._get_indexer_pointwise(target)
  
      elif is_object_dtype(
          target.dtype
      ) or not self._should_partial_index(target):
          # target might contain intervals: defer elementwise to get_loc
          return self._get_indexer_pointwise(target)
  
      else:
          # Note: this case behaves differently from other Index subclasses
          #  because IntervalIndex does partial-int indexing
          target = self._maybe_convert_i8(target)
          indexer, missing = self._engine.get_indexer_non_unique(
              target.values
          )
  
      return ensure_platform_int(indexer), ensure_platform_int(missing)
  
imports: from __future__ import annotations
  from operator import le, lt
  import textwrap
  from typing import TYPE_CHECKING, Any, Literal
  import numpy
  from pandas._libs import lib
  from pandas._libs.interval import Interval, IntervalMixin, IntervalTree
  from pandas._libs.tslibs import BaseOffset, Period, Timedelta, Timestamp, to_offset
  from pandas.errors import InvalidIndexError
  from pandas.util._decorators import Appender, cache_readonly
  from pandas.util._exceptions import rewrite_exception
  from pandas.core.dtypes.cast import find_common_type, infer_dtype_from_scalar, maybe_box_datetimelike, maybe_downcast_numeric, maybe_upcast_numeric_to_64bit
  from pandas.core.dtypes.common import ensure_platform_int, is_float_dtype, is_integer, is_integer_dtype, is_list_like, is_number, is_object_dtype, is_scalar, pandas_dtype
  from pandas.core.dtypes.dtypes import DatetimeTZDtype, IntervalDtype
  from pandas.core.dtypes.missing import is_valid_na_for_dtype
  from pandas.core.algorithms import unique
  from pandas.core.arrays.datetimelike import validate_periods
  from pandas.core.arrays.interval import IntervalArray, _interval_shared_docs
  import pandas.core.common
  from pandas.core.indexers import is_valid_positional_slice
  import pandas.core.indexes.base
  from pandas.core.indexes.base import Index, _index_shared_docs, ensure_index, maybe_extract_name
  from pandas.core.indexes.datetimes import DatetimeIndex, date_range
  from pandas.core.indexes.extension import ExtensionIndex, inherit_names
  from pandas.core.indexes.multi import MultiIndex
  from pandas.core.indexes.timedeltas import TimedeltaIndex, timedelta_range
label_desc: Use image node_id 20 for calling the IntervalIndex obj's underlying member method code with example usage: obj.get_indexer_non_unique(target) and returns: ensure_platform_int,  ensure_platform_int, self, self, self