code: def test_key_val_handler():
      ctx = MockContext()
      assert _cb_key_val(
          ctx, MockOption("profile"), ("nodata=null", "foo=bar")
      ) == {"nodata": None, "foo": "bar"}
  
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 28 for calling a global function with example usage: test_key_val_handler() without return types