code: def validate_api_key(self) -> bool:
      try:
          self.list_instance_types()
      except requests.HTTPError as e:
          if e.response.status_code in [401, 403]:
              return False
          raise e
      return True
  
file_path: dstack/src/dstack/_internal/core/backends/lambdalabs/api_client.py
imports: from typing import Any, Dict, List, Optional
  import requests
label_desc: Use image node_id 2 for calling the LambdaAPIClient obj's underlying member method code with example usage: obj.validate_api_key() and returns: True, False