n_states_1.
If True the mask is kept, otherwise if False it is discarded. Mask will be converted into a bias,
which adds large negative values to the attention scores corresponding to “discard” tokens.   Returns 
UNet2DConditionOutput or tuple
  
If return_dict is True, an UNet2DConditionOutput is returned, otherwise
a tuple is returned where the first element is the sample tensor.
  The AudioLDM2UNet2DConditionModel forward method.  AudioPipel