class_docstr: Internal class used in support of the multiset partitions
  enumerators and the associated visitor functions.
  
  Represents one component of one part of the current partition.
  
  A stack of these, plus an auxiliary frame array, f, represents a
  partition of the multiset.
  
  Knuth's pseudocode makes c, u, and v separate arrays.
docstr: for debug/algorithm animation purposes
docstr_tok: ["for","debug\/algorithm","animation","purposes"]
code: def __repr__(self):
      "for debug/algorithm animation purposes"
      return "c:%d u:%d v:%d" % (self.c, self.u, self.v)
  
label_desc: Use image node_id 2 for calling the PartComponent obj's underlying member method code with example usage: obj.__repr__() and returns: unknown