def __call__(
        self,
        prompt: Optional[Union[str, List[str]]] = None,
        num_images_per_prompt: int = 1,
        prior_num_inference_steps: int = 25,
        decoder_num_inference_steps: int = 25,
        super_res_num_inference_steps: int = 7,
        generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
        prior_latents: Optional[torch.Tensor] = None,
        decoder_latents: Optional[torch.Tensor] = None,
        super_res_latents: Optional[torch.Tensor] = None,
        text_model_output: Optional[Union[CLIPTextModelOutput, Tuple]] = None,
        text_attention_mask: Optional[torch.Tensor] = None,
        prior_guidance_scale: float = 4.0,
        decoder_guidance_scale: float = 8.0,
        output_type: Optional[str] = "pil",
        return_dict: bool = True,
    ):
        """
        The call function to the pipeline for generation.

        Args:
            prompt (`str` or `List[str]`):
                The prompt or prompts to guide image generation. This can only be left undefined if `text_model_output`
                and `text_attention_mask` is passed.
            num_images_per_prompt (`int`, *optional*, defaults to 1):
                The number of images to generate per prompt.
            prior_num_inference_steps (`int`, *optional*, defaults to 25):
                The number of denoising steps for the prior. More denoising steps usually lead to a higher quality
                image at the expense of slower inference.
            decoder_num_inference_steps (`int`, *optional*, defaults to 25):
                The number of denoising steps for the decoder. More denoising steps usually lead to a higher quality
                image at the expense of slower inference.
            super_res_num_inference_steps (`int`, *optional*, defaults to 7):
                The number of denoising steps for super resolution. More denoising steps usually lead to a higher
                quality image at the expense of slower inference.
            generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
                A [`torch.Generator`](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make
                generation deterministic.
            prior_latents (`torch.Tensor` of shape (batch size, embeddings dimension), *optional*):
                Pre-generated noisy latents to be used as inputs for the prior.
            decoder_latents (`torch.Tensor` of shape (batch size, channels, height, width), *optional*):
                Pre-generated noisy latents to be used as inputs for the decoder.
            super_res_latents (`torch.Tensor` of shape (batch size, channels, super res height, super res width), *optional*):
                Pre-generated noisy latents to be used as inputs for the decoder.
            prior_guidance_scale (`float`, *optional*, defaults to 4.0):
                A higher guidance scale value encourages the model to generate images closely linked to the text
                `prompt` at the expense of lower image quality. Guidance scale is enabled when `guidance_scale > 1`.
            decoder_guidance_scale (`float`, *optional*, defaults to 4.0):
                A higher guidance scale value encourages the model to generate images closely linked to the text
                `prompt` at the expense of lower image quality. Guidance scale is enabled when `guidance_scale > 1`.
            text_model_output (`CLIPTextModelOutput`, *optional*):
                Pre-defined [`CLIPTextModel`] outputs that can be derived from the text encoder. Pre-defined text
                outputs can be passed for tasks like text embedding interpolations. Make sure to also pass
                `text_attention_mask` in this case. `prompt` can the be left `None`.
            text_attention_mask (`torch.Tensor`, *optional*):
                Pre-defined CLIP text attention mask that can be derived from the tokenizer. Pre-defined text attention
                masks are necessary when passing `text_model_output`.
            output_type (`str`, *optional*, defaults to `"pil"`):
                The output format of the generated image. Choose between `PIL.Image` or `np.array`.
            return_dict (`bool`, *optional*, defaults to `True`):
                Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.

        Returns:
            [`~pipelines.ImagePipelineOutput`] or `tuple`:
                If `return_dict` is `True`, [`~pipelines.ImagePipelineOutput`] is returned, otherwise a `tuple` is
                returned where the first element is a list with the generated images.
        """
        if prompt is not None:
            if isinstance(prompt, str):
                batch_size = 1
            elif isinstance(prompt, list):
                batch_size = len(prompt)
            else:
                raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}")
        else:
            batch_size = text_model_output[0].shape[0]

        device = self._execution_device

        batch_size = batch_size * num_images_per_prompt

        do_classifier_free_guidance = prior_guidance_scale > 1.0 or decoder_guidance_scale > 1.0

        prompt_embeds, text_enc_hid_states, text_mask = self._encode_prompt(
            prompt, device, num_images_per_prompt, do_classifier_free_guidance, text_model_output, text_attention_mask
        )

        # prior

        self.prior_scheduler.set_timesteps(prior_num_inference_steps, device=device)
        prior_timesteps_tensor = self.prior_scheduler.timesteps

        embedding_dim = self.prior.config.embedding_dim

        prior_latents = self.prepare_latents(
            (batch_size, embedding_dim),
            prompt_embeds.dtype,
            device,
            generator,
            prior_latents,
            self.prior_scheduler,
        )

        for i, t in enumerate(self.progress_bar(prior_timesteps_tensor)):
            # expand the latents if we are doing classifier free guidance
            latent_model_input = torch.cat([prior_latents] * 2) if do_classifier_free_guidance else prior_latents

            predicted_image_embedding = self.prior(
                latent_model_input,
                timestep=t,
                proj_embedding=prompt_embeds,
                encoder_hidden_states=text_enc_hid_states,
                attention_mask=text_mask,
            ).predicted_image_embedding

            if do_classifier_free_guidance:
                predicted_image_embedding_uncond, predicted_image_embedding_text = predicted_image_embedding.chunk(2)
                predicted_image_embedding = predicted_image_embedding_uncond + prior_guidance_scale * (
                    predicted_image_embedding_text - predicted_image_embedding_uncond
                )

            if i + 1 == prior_timesteps_tensor.shape[0]:
                prev_timestep = None
            else:
                prev_timestep = prior_timesteps_tensor[i + 1]

            prior_latents = self.prior_scheduler.step(
                predicted_image_embedding,
                timestep=t,
                sample=prior_latents,
                generator=generator,
                prev_timestep=prev_timestep,
            ).prev_sample

        prior_latents = self.prior.post_process_latents(prior_latents)

        image_embeddings = prior_latents

        # done prior

        # decoder

        text_enc_hid_states, additive_clip_time_embeddings = self.text_proj(
            image_embeddings=image_embeddings,
            prompt_embeds=prompt_embeds,
            text_encoder_hidden_states=text_enc_hid_states,
            do_classifier_free_guidance=do_classifier_free_guidance,
        )

        if device.type == "mps":
            # HACK: MPS: There is a panic when padding bool tensors,
            # so cast to int tensor for the pad and back to bool afterwards
            text_mask = text_mask.type(torch.int)
            decoder_text_mask = F.pad(text_mask, (self.text_proj.clip_extra_context_tokens, 0), value=1)
            decoder_text_mask = decoder_text_mask.type(torch.bool)
        else:
            decoder_text_mask = F.pad(text_mask, (self.text_proj.clip_extra_context_tokens, 0), value=True)

        self.decoder_scheduler.set_timesteps(decoder_num_inference_steps, device=device)
        decoder_timesteps_tensor = self.decoder_scheduler.timesteps

        num_channels_latents = self.decoder.config.in_channels
        height = self.decoder.config.sample_size
        width = self.decoder.config.sample_size

        decoder_latents = self.prepare_latents(
            (batch_size, num_channels_latents, height, width),
            text_enc_hid_states.dtype,
            device,
            generator,
            decoder_latents,
            self.decoder_scheduler,
        )

        for i, t in enumerate(self.progress_bar(decoder_timesteps_tensor)):
            # expand the latents if we are doing classifier free guidance
            latent_model_input = torch.cat([decoder_latents] * 2) if do_classifier_free_guidance else decoder_latents

            noise_pred = self.decoder(
                sample=latent_model_input,
                timestep=t,
                encoder_hidden_states=text_enc_hid_states,
                class_labels=additive_clip_time_embeddings,
                attention_mask=decoder_text_mask,
            ).sample

            if do_classifier_free_guidance:
                noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)
                noise_pred_uncond, _ = noise_pred_uncond.split(latent_model_input.shape[1], dim=1)
                noise_pred_text, predicted_variance = noise_pred_text.split(latent_model_input.shape[1], dim=1)
                noise_pred = noise_pred_uncond + decoder_guidance_scale * (noise_pred_text - noise_pred_uncond)
                noise_pred = torch.cat([noise_pred, predicted_variance], dim=1)

            if i + 1 == decoder_timesteps_tensor.shape[0]:
                prev_timestep = None
            else:
                prev_timestep = decoder_timesteps_tensor[i + 1]

            # compute the previous noisy sample x_t -> x_t-1
            decoder_latents = self.decoder_scheduler.step(
                noise_pred, t, decoder_latents, prev_timestep=prev_timestep, generator=generator
            ).prev_sample

        decoder_latents = decoder_latents.clamp(-1, 1)

        image_small = decoder_latents

        # done decoder

        # super res

        self.super_res_scheduler.set_timesteps(super_res_num_inference_steps, device=device)
        super_res_timesteps_tensor = self.super_res_scheduler.timesteps

        channels = self.super_res_first.config.in_channels // 2
        height = self.super_res_first.config.sample_size
        width = self.super_res_first.config.sample_size

        super_res_latents = self.prepare_latents(
            (batch_size, channels, height, width),
            image_small.dtype,
            device,
            generator,
            super_res_latents,
            self.super_res_scheduler,
        )

        if device.type == "mps":
            # MPS does not support many interpolations
            image_upscaled = F.interpolate(image_small, size=[height, width])
        else:
            interpolate_antialias = {}
            if "antialias" in inspect.signature(F.interpolate).parameters:
                interpolate_antialias["antialias"] = True

            image_upscaled = F.interpolate(
                image_small, size=[height, width], mode="bicubic", align_corners=False, **interpolate_antialias
            )

        for i, t in enumerate(self.progress_bar(super_res_timesteps_tensor)):
            # no classifier free guidance

            if i == super_res_timesteps_tensor.shape[0] - 1:
                unet = self.super_res_last
            else:
                unet = self.super_res_first

            latent_model_input = torch.cat([super_res_latents, image_upscaled], dim=1)

            noise_pred = unet(
                sample=latent_model_input,
                timestep=t,
            ).sample

            if i + 1 == super_res_timesteps_tensor.shape[0]:
                prev_timestep = None
            else:
                prev_timestep = super_res_timesteps_tensor[i + 1]

            # compute the previous noisy sample x_t -> x_t-1
            super_res_latents = self.super_res_scheduler.step(
                noise_pred, t, super_res_latents, prev_timestep=prev_timestep, generator=generator
            ).prev_sample

            if XLA_AVAILABLE:
                xm.mark_step()

        image = super_res_latents
        # done super res

        self.maybe_free_model_hooks()

        # post processing
        image = image * 0.5 + 0.5
        image = image.clamp(0, 1)
        image = image.cpu().permute(0, 2, 3, 1).float().numpy()

        if output_type == "pil":
            image = self.numpy_to_pil(image)

        if not return_dict:
            return (image,)

        return ImagePipelineOutput(images=image)

        The call function to the pipeline for generation.

        Args:
            prompt (`str` or `List[str]`):
                The prompt or prompts to guide image generation. This can only be left undefined if `text_model_output`
                and `text_attention_mask` is passed.
            num_images_per_prompt (`int`, *optional*, defaults to 1):
                The number of images to generate per prompt.
            prior_num_inference_steps (`int`, *optional*, defaults to 25):
                The number of denoising steps for the prior. More denoising steps usually lead to a higher quality
                image at the expense of slower inference.
            decoder_num_inference_steps (`int`, *optional*, defaults to 25):
                The number of denoising steps for the decoder. More denoising steps usually lead to a higher quality
                image at the expense of slower inference.
            super_res_num_inference_steps (`int`, *optional*, defaults to 7):
                The number of denoising steps for super resolution. More denoising steps usually lead to a higher
                quality image at the expense of slower inference.
            generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
                A [`torch.Generator`](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make
                generation deterministic.
            prior_latents (`torch.Tensor` of shape (batch size, embeddings dimension), *optional*):
                Pre-generated noisy latents to be used as inputs for the prior.
            decoder_latents (`torch.Tensor` of shape (batch size, channels, height, width), *optional*):
                Pre-generated noisy latents to be used as inputs for the decoder.
            super_res_latents (`torch.Tensor` of shape (batch size, channels, super res height, super res width), *optional*):
                Pre-generated noisy latents to be used as inputs for the decoder.
            prior_guidance_scale (`float`, *optional*, defaults to 4.0):
                A higher guidance scale value encourages the model to generate images closely linked to the text
                `prompt` at the expense of lower image quality. Guidance scale is enabled when `guidance_scale > 1`.
            decoder_guidance_scale (`float`, *optional*, defaults to 4.0):
                A higher guidance scale value encourages the model to generate images closely linked to the text
                `prompt` at the expense of lower image quality. Guidance scale is enabled when `guidance_scale > 1`.
            text_model_output (`CLIPTextModelOutput`, *optional*):
                Pre-defined [`CLIPTextModel`] outputs that can be derived from the text encoder. Pre-defined text
                outputs can be passed for tasks like text embedding interpolations. Make sure to also pass
                `text_attention_mask` in this case. `prompt` can the be left `None`.
            text_attention_mask (`torch.Tensor`, *optional*):
                Pre-defined CLIP text attention mask that can be derived from the tokenizer. Pre-defined text attention
                masks are necessary when passing `text_model_output`.
            output_type (`str`, *optional*, defaults to `"pil"`):
                The output format of the generated image. Choose between `PIL.Image` or `np.array`.
            return_dict (`bool`, *optional*, defaults to `True`):
                Whether or not to return a [`~pipelines.ImagePipelineOutput`] instead of a plain tuple.

        Returns:
            [`~pipelines.ImagePipelineOutput`] or `tuple`:
                If `return_dict` is `True`, [`~pipelines.ImagePipelineOutput`] is returned, otherwise a `tuple` is
                returned where the first element is a list with the generated images.
        
src/diffusers/pipelines/unclip/pipeline_unclip.py