src/transformers/models/mvp/modeling_mvp.py/MvpPrompt/__init__
class MvpPrompt:    def __init__(self, config, num_layers, num_heads):
        super().__init__()
        self.prompt_length = config.prompt_length
        self.num_layers = num_layers
        self.num_heads = num_heads
        self.head_dim = config.d_model // num_heads
        self.dropout = nn.Dropout(p=config.dropout)
        self.prompt_embedding = nn.Embedding(config.prompt_length, config.d_model)
        self.prompt_trans = nn.Sequential(
            nn.Linear(config.d_model, config.prompt_mid_dim),
            nn.GELU(),
            nn.Linear(config.prompt_mid_dim, num_layers * 2 * config.d_model),
        )