code: def list_backend_types(self) -> List[BackendType]:
      resp = self._request("/api/backends/list_types")
      return parse_obj_as(List[BackendType], resp.json())
  
file_path: dstack/src/dstack/api/server/_backends.py
imports: from typing import List
  from pydantic import parse_obj_as
  from dstack._internal.core.models.backends import AnyConfigInfoWithCreds, AnyConfigInfoWithCredsPartial, AnyConfigValues
  from dstack._internal.core.models.backends.base import BackendType
  from dstack._internal.server.schemas.backends import DeleteBackendsRequest
  from dstack.api.server._group import APIClientGroup
label_desc: Use image node_id 1 for calling the BackendsAPIClient obj's underlying member method code with example usage: obj.list_backend_types() and returns: parse_obj_as