class_docstr: Base class for a vertex.
class_docstr_tok: ["Base","class","for","a","vertex","."]
docstr: Initiation of a vertex object.
  
  Parameters
  ----------
  x : tuple or vector
      The geometric location (domain).
  nn : list, optional
      Nearest neighbour list.
  index : int, optional
      Index of vertex.
docstr_tok: ["Initiation","of","a","vertex","object",".","Parameters","--","--","--","--","--","x",":","tuple","or","vector","The","geometric","location","(","domain",")",".","nn",":","list",",","optional","Nearest","neighbour","list",".","index",":","int",",","optional","Index","of","vertex","."]
code: def __init__(self, x, nn=None, index=None):
      """
      Initiation of a vertex object.
  
      Parameters
      ----------
      x : tuple or vector
          The geometric location (domain).
      nn : list, optional
          Nearest neighbour list.
      index : int, optional
          Index of vertex.
      """
      self.x = x
      self.hash = hash(self.x)  # Save precomputed hash
  
      if nn is not None:
          self.nn = set(nn)  # can use .indexupdate to add a new list
      else:
          self.nn = set()
  
      self.index = index
  
imports: import collections
  from abc import ABC, abstractmethod
  import numpy
  from scipy._lib._util import MapWrapper
label_desc: Use image node_id 1 to create a new VertexBase object from inherited base classes: ABC with example: obj = VertexBase(x, nn, index)