code: def generate(self, prompt: str, img_size: int = 512):
      assert len(prompt), "prompt parameter cannot be empty"
      logger.info("Prompt: [%s]", prompt)
      image = self.pipe(prompt, height=img_size, width=img_size).images[
          0
      ]
      return image
  
file_path: ray/release/workspace_templates/03_serving_stable_diffusion/app.py
imports: from io import BytesIO
  from ray import serve
  from fastapi import FastAPI
  from fastapi.responses import Response
  import torch
  from diffusers import EulerDiscreteScheduler, StableDiffusionPipeline
  import logging
label_desc: Use image node_id 2 for calling the StableDiffusionV2 obj's underlying member method code with example usage: obj.generate(prompt, img_size) and returns: image