code: def get_streamlines():
      from dipy.data import get_fnames
      from dipy.io.streamline import load_tractogram
  
      fname = get_fnames("fornix")
      fornix = load_tractogram(fname, "same", bbox_valid_check=False)
  
      return fornix.streamlines
  
imports: import numpy
  from dipy.segment.clustering import QuickBundles
  from dipy.segment.metric import AveragePointwiseEuclideanMetric, SumPointwiseEuclideanMetric, CosineMetric
  from dipy.segment.featurespeed import VectorOfEndpointsFeature
  from dipy.tracking.streamline import set_number_of_points
  from dipy.viz import window, actor, colormap
label_desc: Use image node_id 1 for calling a global function with example usage: get_streamlines() and returns: fornix