code: def test_nodata_callback_pass(data):
      """Always return None if the value is None"""
      ctx = MockContext()
      assert nodata_handler(ctx, MockOption("nodata"), None) is None
  
imports: import math
  import uuid
  import click
  import pytest
  from rasterio.enums import ColorInterp
  from rasterio.rio.options import bounds_handler, file_in_handler, like_handler, edit_nodata_handler, nodata_handler, _cb_key_val
label_desc: Use image node_id 18 for calling a global function with example usage: test_nodata_callback_pass(data) without return types