class_docstr: Class to specify multiple possibles value for a given field in ast.
  
  Attributes
  ----------
  args: [ast field value]
      List of possible value for a field of an ast.
class_docstr_tok: ["Class","to","specify","multiple","possibles","value","for","a","given","field","in","ast",".","Attributes","--","--","--","--","--","args",":","[","ast","field","value","]","List","of","possible","value","for","a","field","of","an","ast","."]
docstr: Initialiser to keep track of arguments. 
docstr_tok: ["Initialiser","to","keep","track","of","arguments","."]
code: def __init__(self, *args):
      """Initialiser to keep track of arguments."""
      self.args = args
      super(AST_or, self).__init__()
  
imports: from gast import AST, iter_fields, NodeVisitor, Dict, Set
  from itertools import permutations
  from math import isnan
label_desc: Use image node_id 1 to create a new AST_or object from inherited base classes: AST with example: obj = AST_or()