class_docstr: A case-insensitive map of string keys to values.
  
  This is used by Python data source options to ensure consistent case insensitivity.
code: def update(self, *args: Any, **kwargs: Any) -> None:
      for k, v in dict(*args, **kwargs).items():
          self[k] = v
  
imports: from abc import ABC, abstractmethod
  from collections import UserDict
  from typing import Any, Dict, Iterator, List, Sequence, Tuple, Type, Union, TYPE_CHECKING
  from pyspark.sql import Row
  from pyspark.sql.types import StructType
  from pyspark.errors import PySparkNotImplementedError
label_desc: Use image node_id 6 for calling the CaseInsensitiveDict obj's underlying member method code with example usage: obj.update() without return types