class_docstr: Validates values that will be used as keys.
  
  :param max_length:
      The maximum allowed length of the given key
class_docstr_tok: ["Validates","values","that","will","be","used","as","keys",".",":","param","max_length",":","The","maximum","allowed","length","of","the","given","key"]
code: def __init__(self, max_length=200):
      self.max_length = max_length
  
file_path: airflow/airflow/www/validators.py
imports: from __future__ import annotations
  import json
  from json import JSONDecodeError
  from wtforms.validators import EqualTo, ValidationError
  from airflow.models.connection import CONN_ID_MAX_LEN, sanitize_conn_id
  from airflow.utils import helpers
label_desc: Use image node_id 1 to create a new ValidKey object  with example: obj = ValidKey(max_length)