code: def is_valid_cvas(self) -> bool:
      parsed = sqlparse.parse(self.strip_comments())
      return len(parsed) == 1 and parsed[0].get_type() == "SELECT"
  
imports: import logging
  import re
  from collections.abc import Iterator
  from dataclasses import dataclass
  from typing import Any, cast, Optional
  from urllib import parse
  import sqlparse
  from sqlalchemy import and_
  from sqlparse import keywords
  from sqlparse.lexer import Lexer
  from sqlparse.sql import Identifier, IdentifierList, Parenthesis, remove_quotes, Token, TokenList, Where
  from sqlparse.tokens import Comment, CTE, DDL, DML, Keyword, Name, Punctuation, String, Whitespace, Wildcard
  from sqlparse.utils import imt
  from superset.exceptions import QueryClauseValidationException
  from superset.utils.backports import StrEnum
label_desc: Use image node_id 9 for calling the ParsedQuery obj's underlying member method code with example usage: obj.is_valid_cvas() and returns: unknown