[`~models.unet_2d_blocks.UNetMidBlock2DCrossAttn`].
transformer_layers_per_mid_block (`int` or `Tuple[int]`, *optional*, defaults to 1):
The number of transformer layers to use in each layer in the middle block.
attention_head_dim (`int` or `Tuple[int]`, defaults to 8):
The dimension of the attention heads.
num_attention_heads (`int` or `Tuple[int]`, *optional*):
The number of heads to use for multi-head attention.
use_linear_projection (`bool`, defaults to `False`):