src/transformers/models/lxmert/modeling_lxmert.py/LxmertPreTrainingHeads/__init__
class LxmertPreTrainingHeads:    def __init__(self, config, lxmert_model_embedding_weights):
        super(LxmertPreTrainingHeads, self).__init__()
        self.predictions = LxmertLMPredictionHead(config, lxmert_model_embedding_weights)
        self.seq_relationship = nn.Linear(config.hidden_size, 2)