code: def test_delegation_unknown_scalar(arr):
      s = UnknownScalar()
      assert arr * s == 42
      assert s * arr == 42
      with pytest.raises(
          TypeError,
          match="operand 'UnknownScalar' does not support ufuncs",
      ):
          np.multiply(s, arr)
  
imports: from __future__ import annotations
  import operator
  import numpy
  import pytest
  import dask.array
  from dask.array import Array
  from dask.array.chunk_types import is_valid_array_chunk, is_valid_chunk_type
  from dask.array.utils import assert_eq
label_desc: Use image node_id 8 for calling a global function with example usage: test_delegation_unknown_scalar(arr) without return types