code: def forward_post(self, tgt):
      tgt2 = self.linear2(
          self.dropout(self.activation(self.linear1(tgt)))
      )
      tgt = tgt + self.dropout(tgt2)
      tgt = self.norm(tgt)
      return tgt
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import param_init
  from paddlepanseg.models.param_init import c2_xavier_fill, THLinearInitMixin, th_linear_fill, th_multihead_fill
  from .common import Conv2D, PositionEmbeddingSine
label_desc: Use image node_id 4 for calling the FFNLayer obj's underlying member method code with example usage: obj.forward_post(tgt) and returns: tgt