class_docstr: Deque implementation using a numpy array as a circular buffer.
code: def clear(self):
      self._start_index = np.int64(0)
      self._len = np.int64(0)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import abc
  from typing import Any, Iterable, Optional, Text
  import gin
  import numpy
  import six
  from tf_agents.metrics import py_metric
  from tf_agents.trajectories import trajectory
  from tf_agents.typing import types
  from tf_agents.utils import nest_utils
  from tf_agents.utils import numpy_storage
label_desc: Use image node_id 2 for calling the NumpyDeque obj's underlying member method code with example usage: obj.clear() without return types