code: def test_non_hlg():
      # Regression test for https://github.com/dask/dask/issues/5850
      a = da.from_array(np.ones(1, np.float64), chunks=(1,))
      a.dask = dict(a.dask)  # Convert from HighLevelGraph to plain dict
      b = da.from_array(np.zeros(1, np.float64), chunks=(1,))
      x = a + b
      assert_eq(x, a)
  
imports: from __future__ import annotations
  import collections
  from operator import add
  import numpy
  import pytest
  import dask
  import dask.array
  from dask.array.utils import assert_eq
  from dask.blockwise import _BLOCKWISE_DEFAULT_PREFIX, Blockwise, _unique_dep, index_subs, optimize_blockwise, rewrite_blockwise
  from dask.highlevelgraph import HighLevelGraph
  from dask.utils_test import dec, hlg_layer_topological, inc
label_desc: Use image node_id 31 for calling a global function with example usage: test_non_hlg() without return types