src/transformers/models/longformer/modeling_longformer.py/LongformerOutput/forward
class LongformerOutput:    def forward(self, hidden_states, input_tensor):
        hidden_states = self.dense(hidden_states)
        hidden_states = self.dropout(hidden_states)
        hidden_states = self.LayerNorm(hidden_states + input_tensor)
        return hidden_states