code: def forward(self, x):
      for i, layer in enumerate(self.layers):
          x = F.relu(layer(x)) if i < self.num_layers - 1 else layer(x)
  
      return x
  
imports: import math
  import copy
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.models import layers
  from paddleseg.cvlibs import manager, param_init
  from paddleseg.utils import utils
  from paddleseg.core.train import check_logits_losses
label_desc: Use image node_id 3 for calling the MLP obj's underlying member method code with example usage: obj.forward(x) and returns: x