code: def store_evolution_in(lst):
      """Returns a callback function to store the evolution of the level sets in
      the given list.
      """
  
      def _store(x):
          lst.append(np.copy(x))
  
      return _store
  
imports: import numpy
  import matplotlib.pyplot
  from skimage import data, img_as_float
  from skimage.segmentation import morphological_chan_vese, morphological_geodesic_active_contour, inverse_gaussian_gradient, checkerboard_level_set
label_desc: Use image node_id 1 for calling a global function with example usage: store_evolution_in(lst) and returns: _store