code: def test_pipe_close_empty_before_read(self):
      pipe = Pipe()
  
      buf = []
      timeout = 1.0
  
      def read():
          buf.append(pipe.read())
  
      thread = in_thread(read)
      thread.join(timeout)
      self.assertEqual(True, thread.is_alive())
  
      pipe.close()
      thread.join(timeout)
      self.assertEqual(False, thread.is_alive())
      self.assertEqual([None], buf)
  
file_path: horovod/test/single/test_util.py
imports: import unittest
  from horovod.runner.util.streams import Pipe
  from horovod.runner.util.threads import in_thread
label_desc: Use image node_id 3 for calling the UtilTests obj's underlying member method code with example usage: obj.test_pipe_close_empty_before_read() without return types