docstr: Return configuration parameters as OpenAPI.
code: def parameters_json_schema(cls) -> Any:
      """
      Return configuration parameters as OpenAPI.
      """
      if not cls.parameters_schema:
          return None
  
      ma_plugin = MarshmallowPlugin()
      spec = APISpec(
          title="Database Parameters",
          version="1.0.0",
          openapi_version="3.0.0",
          plugins=[ma_plugin],
      )
  
      spec.components.schema(cls.__name__, schema=cls.parameters_schema)
      return spec.to_dict()["components"]["schemas"][cls.__name__]
  
imports: import json
  import logging
  import re
  from datetime import datetime
  from re import Pattern
  from typing import Any, Optional, TYPE_CHECKING, TypedDict
  from urllib import parse
  from apispec import APISpec
  from apispec.ext.marshmallow import MarshmallowPlugin
  from cryptography.hazmat.backends import default_backend
  from cryptography.hazmat.primitives import serialization
  from flask import current_app
  from flask_babel import gettext
  from marshmallow import fields, Schema
  from sqlalchemy import types
  from sqlalchemy.engine.reflection import Inspector
  from sqlalchemy.engine.url import URL
  from superset.constants import TimeGrain, USER_AGENT
  from superset.databases.utils import make_url_safe
  from superset.db_engine_specs.base import BaseEngineSpec, BasicPropertiesType
  from superset.db_engine_specs.postgres import PostgresBaseEngineSpec
  from superset.errors import ErrorLevel, SupersetError, SupersetErrorType
  from superset.models.sql_lab import Query
label_desc: Use image node_id 14 for calling the SnowflakeEngineSpec obj's underlying member method code with example usage: obj.parameters_json_schema(cls) and returns: spec, None