parameters: (self,
                           node_name,
                           output_slot,
                           debug_op,
                           device_name=None)
return_statement: return self._watch_key_to_rel_time[device_name][watch_key]
docstring: Get the relative timestamp from for a debug-dumped tensor.
  
      Relative timestamp means (absolute timestamp - `t0`), where `t0` is the
      absolute timestamp of the first dumped tensor in the dump root. The tensor
      may be dumped multiple times in the dump root directory, so a list of
      relative timestamps (`numpy.ndarray`) is returned.
  
      Args:
        node_name: (`str`) name of the node that the tensor is produced by.
        output_slot: (`int`) output slot index of tensor.
        debug_op: (`str`) name of the debug op.
        device_name: (`str`) name of the device. If there is only one device or if
          the specified debug_watch_key exists on only one device, this argument
          is optional.
  
      Returns:
        (`list` of `int`) list of relative timestamps.
  
      Raises:
        WatchKeyDoesNotExistInDebugDumpDirError: If the tensor watch key does not
          exist in the debug dump data.
docstring_summary: Get the relative timestamp from for a debug-dumped tensor.
docstring_tokens: Get the relative timestamp from for a debug - dumped tensor .
function: def get_rel_timestamps(self,
                           node_name,
                           output_slot,
                           debug_op,
                           device_name=None):
      """Get the relative timestamp from for a debug-dumped tensor.
  
      Relative timestamp means (absolute timestamp - `t0`), where `t0` is the
      absolute timestamp of the first dumped tensor in the dump root. The tensor
      may be dumped multiple times in the dump root directory, so a list of
      relative timestamps (`numpy.ndarray`) is returned.
  
      Args:
        node_name: (`str`) name of the node that the tensor is produced by.
        output_slot: (`int`) output slot index of tensor.
        debug_op: (`str`) name of the debug op.
        device_name: (`str`) name of the device. If there is only one device or if
          the specified debug_watch_key exists on only one device, this argument
          is optional.
  
      Returns:
        (`list` of `int`) list of relative timestamps.
  
      Raises:
        WatchKeyDoesNotExistInDebugDumpDirError: If the tensor watch key does not
          exist in the debug dump data.
      """
  
      device_name = self._infer_device_name(device_name, node_name)
      watch_key = _get_tensor_watch_key(node_name, output_slot, debug_op)
      if watch_key not in self._watch_key_to_datum[device_name]:
        raise WatchKeyDoesNotExistInDebugDumpDirError(
            "Watch key \"%s\" does not exist in the debug dump" % watch_key)
  
      # TODO(cais): Figure out whether this should be relative to the global t0.
      return self._watch_key_to_rel_time[device_name][watch_key]
function_tokens: def get_rel_timestamps ( self , node_name , output_slot , debug_op , device_name = None ) : device_name = self . _infer_device_name ( device_name , node_name ) watch_key = _get_tensor_watch_key ( node_name , output_slot , debug_op ) if watch_key not in self . _watch_key_to_datum [ device_name ] : raise WatchKeyDoesNotExistInDebugDumpDirError ( "Watch key \"%s\" does not exist in the debug dump" % watch_key ) # TODO(cais): Figure out whether this should be relative to the global t0. return self . _watch_key_to_rel_time [ device_name ] [ watch_key ]