ion_dim (int or Tuple[int], optional, defaults to 1280) —
The dimension of the cross attention features.   transformer_layers_per_block (int, Tuple[int], or Tuple[Tuple] , optional, defaults to 1) —
The number of transformer blocks of type BasicTransformerBlock. Only relevant for
~models.unet_2d_blocks.CrossAttnDownBlock2D, ~models.unet_2d_blocks.CrossAttnUpBlock2D,
~models.unet_2d_blocks.UNetMidBlock2DCrossAttn.    A conditional 2D UNet model 