code: def forward(self, x):
      out = x
      for idx in range(self._num_modules):
          out = self.stage_func_list[idx](out)
      return out
  
imports: import math
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import manager, param_init
  from paddleseg.models import layers
  from paddleseg.utils import utils
label_desc: Use image node_id 2 for calling the Stage obj's underlying member method code with example usage: obj.forward(x) and returns: out