code: def _null_array_to_array_payload(
      a: "pyarrow.NullArray",
  ) -> "PicklableArrayPayload":
      """Serialize null array to PicklableArrayPayload."""
      # Buffer scheme: [None]
      return PicklableArrayPayload(
          type=a.type,
          length=len(a),
          buffers=[None],  # Single null buffer is expected.
          null_count=a.null_count,
          offset=0,
          children=[],
      )
  
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 14 for calling a global function with example usage: _null_array_to_array_payload(a) and returns: PicklableArrayPayload