tuple.    The Transformer2DModel forward method.  Transformer2DModelOutput  class diffusers.models.transformers.transformer_2d.Transformer2DModelOutput  < source > ( sample: FloatTensor  )   Parameters   sample (torch.FloatTensor of shape (batch_size, num_channels, height, width) or (batch size, num_vector_embeds - 1, num_latent_pixels) if Transformer2DModel is discrete) —