class_docstr: Very simple multi-layer perceptron (also called FFN)
class_docstr_tok: ["Very","simple","multi-layer","perceptron","(","also","called","FFN",")"]
code: def forward(self, x: Tensor):
      for i, layer in enumerate(self.layers):
          x = F.relu(layer(x)) if i < self.num_layers - 1 else layer(x)
      return x
  
imports: from typing import Optional
  import torch
  import torch.nn.functional
  from mmf.models.unit.backbone import build_unit_convnet_backbone
  from mmf.models.unit.matcher import HungarianMatcher
  from mmf.models.unit.misc import NestedTensor
  from mmf.models.unit.transformer import UniTTransformer
  from mmf.utils import box_ops
  from mmf.utils.distributed import get_world_size, is_dist_initialized
  from torch import nn, Tensor
label_desc: Use image node_id 2 for calling the MLP obj's underlying member method code with example usage: obj.forward(x) and returns: x