The hidden size of the attention layer.
cross_attention_dim (`int`, *optional*, defaults to `None`):
The number of channels in the `encoder_hidden_states`.
out_bias (`bool`, defaults to `True`):
Whether to include the bias parameter in `train_q_out`.
dropout (`float`, *optional*, defaults to 0.0):
The dropout probability to use.  
CustomDiffusionAttnProcessor  
Processor for implementing attention for the Custom Diffusion method.  
Args:
train_kv (`bool`, defaults to `True`):