class_docstr: A special data structure needed by FonsecaHyperVolume.
  
  It consists of several doubly linked lists that share common nodes. So,
  every node has multiple predecessors and successors, one in every list.
class_docstr_tok: ["A","special","data","structure","needed","by","FonsecaHyperVolume",".","It","consists","of","several","doubly","linked","lists","that","share","common","nodes",".","So",",","every","node","has","multiple","predecessors","and","successors",",","one","in","every","list","."]
docstr: Returns the number of lists that are included in this _MultiList.
docstr_tok: ["Returns","the","number","of","lists","that","are","included","in","this","_MultiList","."]
code: def __len__(self):
      """Returns the number of lists that are included in this _MultiList."""
      return self.numberLists
  
file_path: deap/deap/tools/_hypervolume/pyhv.py
imports: import warnings
  import numpy
label_desc: Use image node_id 3 for calling the _MultiList obj's underlying member method code with example usage: obj.__len__() and returns: self