class_docstr: A class for visiting FunctionDef nodes in an abstract syntax tree (AST).
  
  This class extends the ast.NodeVisitor class and is used to extract all
  functions (not part of any class) in the Python source code.
  
  Attributes
  ----------
  funcs : list
      A list of FunctionDef nodes that are not part of any class.
  inside_class : bool
      A flag indicating whether the current node being visited is inside a class.
  
  Methods
  -------
  visit_FunctionDef(node) :
      Extracts the FunctionDef node if it is not part of any class.
  visit_ClassDef(node) :
      Sets the inside_class flag to True when entering a ClassDef node and to False when leaving.
class_docstr_tok: ["A","class","for","visiting","FunctionDef","nodes","in","an","abstract","syntax","tree","(","AST",")",".","This","class","extends","the","ast.NodeVisitor","class","and","is","used","to","extract","all","functions","(","not","part","of","any","class",")","in","the","Python","source","code",".","Attributes","--","--","--","--","--","funcs",":","list","A","list","of","FunctionDef","nodes","that","are","not","part","of","any","class",".","inside_class",":","bool","A","flag","indicating","whether","the","current","node","being","visited","is","inside","a","class",".","Methods","--","--","--","-","visit_FunctionDef","(","node",")",":","Extracts","the","FunctionDef","node","if","it","is","not","part","of","any","class",".","visit_ClassDef","(","node",")",":","Sets","the","inside_class","flag","to","True","when","entering","a","ClassDef","node","and","to","False","when","leaving","."]
code: def visit_FunctionDef(self, node):
      if not self.inside_class:
          self.funcs.append(node)
      self.generic_visit(node)
  
imports: import ast
  import json
  import re
  import argparse
  import textwrap
  import os
  from collections import defaultdict
label_desc: Use image node_id 2 for calling the FunctionVisitor obj's underlying member method code with example usage: obj.visit_FunctionDef(node) without return types