class_docstr: Wrapper for AST query.
  Intended to ind, track, update last values in query
class_docstr_tok: ["Wrapper","for","AST","query",".","Intended","to","ind",",","track",",","update","last","values","in","query"]
code: def get_init_queries(self):
      back_up_values = []
      # replace values
      for nodes in self.last_idx.values():
          for node in nodes:
              back_up_values.append([node.op, node.args[1]])
              node.op = "is not"
              node.args[1] = NullConstant()
  
      query2 = copy.deepcopy(self.query)
  
      # return values
      for nodes in self.last_idx.values():
          for node in nodes:
              op, arg1 = back_up_values.pop(0)
              node.op = op
              node.args[1] = arg1
  
      for info in self.get_last_columns():
          col = Identifier(info["column_name"])
          query2.targets = [col]
          query2.order_by = [OrderBy(col, direction="DESC")]
          query2.limit = Constant(1)
          yield query2, info
  
file_path: mindsdb/mindsdb/interfaces/query_context/last_query.py
imports: from typing import Union, List
  import copy
  from collections import defaultdict
  from mindsdb_sql.parser.ast import Identifier, Select, BinaryOperation, Last, Constant, Star, ASTNode, NullConstant, OrderBy
  from mindsdb_sql.planner.utils import query_traversal
label_desc: Use image node_id 6 for calling the LastQuery obj's underlying member method code with example usage: obj.get_init_queries() without return types