code: def test_disable_lowlevel_fusion():
      """Check that by disabling fusion, the HLG survives through optimizations"""
  
      with dask.config.set({"optimization.fuse.active": False}):
          y = da.ones(3, chunks=(3,), dtype="int")
          optimize = y.__dask_optimize__
          dsk1 = y.__dask_graph__()
          dsk2 = optimize(dsk1, y.__dask_keys__())
          assert isinstance(dsk1, HighLevelGraph)
          assert isinstance(dsk2, HighLevelGraph)
          assert dsk1 == dsk2
          y = y.persist()
          assert isinstance(y.__dask_graph__(), HighLevelGraph)
          assert_eq(y, [1] * 3)
  
imports: from __future__ import annotations
  import pytest
  import numpy
  import dask
  import dask.array
  from dask.array.chunk import getitem
  from dask.array.core import getter
  from dask.array.core import getter_nofancy
  from dask.array.optimization import _is_getter_task, fuse_slice, optimize, optimize_blockwise, optimize_slices
  from dask.array.utils import assert_eq
  from dask.highlevelgraph import HighLevelGraph
  from dask.optimization import SubgraphCallable, fuse
  from dask.utils import SerializableLock
label_desc: Use image node_id 22 for calling a global function with example usage: test_disable_lowlevel_fusion() without return types