code: def test_sink_destroy():
      source = Stream()
      sink = Sink(source)
      ref = weakref.ref(sink)
      sink.destroy()
  
      assert sink not in _global_sinks
  
      del sink
  
      assert ref() is None
  
file_path: streamz/streamz/tests/test_sinks.py
imports: import weakref
  import pytest
  from streamz import Stream
  from streamz.sinks import _global_sinks, Sink
  from streamz.utils_test import tmpfile, wait_for
label_desc: Use image node_id 5 for calling a global function with example usage: test_sink_destroy() without return types