code: def forward(self, tgt):
      if self.normalize_before:
          return self.forward_pre(tgt)
      return self.forward_post(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 6 for calling the FFNLayer obj's underlying member method code with example usage: obj.forward(tgt) and returns: self, self