class_docstr: Abstract class for KVStore defining APIs needed for ray serve
  use cases, currently (8/6/2021) controller state checkpointing.
docstr: Delete an object.
  
  Args:
      key: Key for object to be deleted.
docstr_tok: ["Delete","an","object",".","Args",":","key",":","Key","for","object","to","be","deleted","."]
code: def delete(self, key: str) -> None:
      """Delete an object.
  
      Args:
          key: Key for object to be deleted.
      """
      raise NotImplementedError("delete() has to be implemented")
  
file_path: ray/python/ray/serve/_private/storage/kv_store_base.py
imports: import abc
  from abc import abstractmethod
  from typing import Optional
  from ray.util.annotations import DeveloperAPI
label_desc: Use image node_id 4 for calling the KVStoreBase obj's underlying member method code with example usage: obj.delete(key) without return types