)  __call__  < source > ( prompt: Union = None images: Union = None height: int = 1024 width: int = 1024 num_inference_steps: int = 20 timesteps: List = None guidance_scale: float = 4.0 negative_prompt: Union = None prompt_embeds: Optional = None prompt_embeds_pooled: Optional = None negative_prompt_embeds: Optional = None negative_prompt_embeds_pooled: Optional = None image_embeds: Optional = None num_images_per_prompt: Optional = 1 generator: