e generic methods
implemented for all pipelines (downloading, saving, running on a particular device, etc.).  __call__  < source > ( prompt: Union prompt_2: Union = None video_length: Optional = 8 height: Optional = None width: Optional = None num_inference_steps: int = 50 denoising_end: Optional = None guidance_scale: float = 7.5 negative_prompt: Union = None negative_prompt_2: Union = None num_videos_per_prompt: Optional = 1 eta: float = 0.0 