code: def stream_type(experience: "ClassificationExperience") -> str:
      """
      Returns the stream name from which the experience belongs to.
      e.g. the experience can be part of train or test stream.
  
      :param experience: the instance of the experience
      """
  
      return experience.origin_stream.name
  
file_path: avalanche/avalanche/evaluation/metric_utils.py
imports: from typing import Dict, Optional, Union, Iterable, Sequence, Tuple, TYPE_CHECKING, List, Callable, Any
  import matplotlib.pyplot
  import numpy
  from matplotlib.axes import Axes
  from numpy import ndarray, arange
  from torch import Tensor
label_desc: Use image node_id 5 for calling a global function with example usage: stream_type(experience) and returns: experience