class_docstr: Timeout class using ALARM signal.
code: def __enter__(self):
      if signal is None:
          raise WindowsError("Windows is not supported for this test")
  
      signal.signal(signal.SIGALRM, self.raise_timeout)
      signal.alarm(self.sec)
  
file_path: TensorLayer/tests/utils/timeout_utils.py
imports: import platform
label_desc: Use image node_id 2 for calling the TimeoutContext obj's underlying member method code with example usage: obj.__enter__() without return types