merBlock attention should contain a bias parameter.   sample_size (int, optional) — The width of the latent images (specify if the input is discrete).
This is fixed during training since it is used to learn a number of position embeddings.   activation_fn (str, optional, defaults to "geglu") —
Activation function to use in feed-forward. See diffusers.models.activations.get_activation for supported
activation functions.   norm_elementwise_affine