code: def _copy_buffer_if_needed(
      buf: "pyarrow.Buffer",
      type_: Optional["pyarrow.DataType"],
      offset: int,
      length: int,
  ) -> "pyarrow.Buffer":
      """Copy buffer, if needed."""
      import pyarrow as pa
  
      if type_ is not None and pa.types.is_boolean(type_):
          # Arrow boolean array buffers are bit-packed, with 8 entries per byte,
          # and are accessed via bit offsets.
          buf = _copy_bitpacked_buffer_if_needed(buf, offset, length)
      else:
          type_bytewidth = (
              type_.bit_width // 8 if type_ is not None else 1
          )
          buf = _copy_normal_buffer_if_needed(
              buf, type_bytewidth, offset, length
          )
      return buf
  
imports: from dataclasses import dataclass
  import logging
  import os
  import sys
  from typing import List, Tuple, Optional, TYPE_CHECKING
label_desc: Use image node_id 24 for calling a global function with example usage: _copy_buffer_if_needed(buf, type_, offset, length) and returns: buf