tention_heads * attention_head_dim`   embedding_proj_dim (int, optional, default to None) —
The dimension of proj_embedding. If None, will be set to embedding_dim.   clip_embed_dim (int, optional, default to None) —
The dimension of the output. If None, will be set to embedding_dim.    A Prior Transformer model.  forward  < source > ( hidden_states timestep: Union proj_embedding: FloatTensor encoder_hidden_states: Optional = None attention_mask