code: def deserialize_callback_handler(
      callback_name: str,
  ) -> Optional[Callable[[StreamingChunk], None]]:
      """
      Deserializes the streaming callback handler.
      :param callback_name: The full path of the streaming callback handler function
      :return: The streaming callback handler function
      :raises DeserializationError: If the streaming callback handler function cannot be found
      """
      parts = callback_name.split(".")
      module_name = ".".join(parts[:-1])
      function_name = parts[-1]
      module = sys.modules.get(module_name, None)
      if not module:
          raise DeserializationError(
              f"Could not locate the module of the streaming callback: {module_name}"
          )
      streaming_callback = getattr(module, function_name, None)
      if not streaming_callback:
          raise DeserializationError(
              f"Could not locate the streaming callback: {function_name}"
          )
      return streaming_callback
  
imports: import inspect
  import sys
  from typing import Optional, Callable
  from haystack import DeserializationError
  from haystack.dataclasses import StreamingChunk
label_desc: Use image node_id 3 for calling a global function with example usage: deserialize_callback_handler(callback_name) and returns: streaming_callback