code: def visitDefault(self, node):
      ids = set()
      for child in self.children(node):
          if isinstance(child, (tuple, list)):
              for item in child:
                  ids.update(self.visit(item))
  
          elif isinstance(child, ast.AST):
              ids.update(self.visit(child))
  
      return ids
  
file_path: turicreate/src/python/turicreate/meta/asttools/visitors/symbol_visitor.py
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from ...asttools.visitors import Visitor
  import ast
label_desc: Use image node_id 2 for calling the SymbolVisitor obj's underlying member method code with example usage: obj.visitDefault(node) and returns: ids