code: def forward(self, x, targets=None):
      x = x.transpose([0, 2, 3, 1])
      _, H, W, C = x.shape
      feature = x.flatten(1, 2)
      feature = self.pos_encoder(feature)
      for encoder_layer in self.encoder:
          feature = encoder_layer(feature)
      feature = feature.reshape([0, H, W, C]).transpose([0, 3, 1, 2])
      v_feature, attn_scores = self.decoder(
          feature
      )  # (B, N, C), (B, C, H, W)
      vis_logits = self.cls(v_feature)  # (B, N, C)
      logits = vis_logits
      vis_lengths = _get_length(vis_logits)
      if self.use_lang:
          align_logits = vis_logits
          align_lengths = vis_lengths
          all_l_res, all_a_res = [], []
          for i in range(self.iter_size):
              tokens = F.softmax(align_logits, axis=-1)
              lengths = align_lengths
              lengths = paddle.clip(
                  lengths, 2, self.max_length
              )  # TODO:move to langauge model
              l_feature, l_logits = self.language(tokens, lengths)
  
              # alignment
              all_l_res.append(l_logits)
              fuse = paddle.concat((l_feature, v_feature), -1)
              f_att = F.sigmoid(self.w_att_align(fuse))
              output = f_att * v_feature + (1 - f_att) * l_feature
              align_logits = self.cls_align(output)  # (B, N, C)
  
              align_lengths = _get_length(align_logits)
              all_a_res.append(align_logits)
          if self.training:
              return {
                  "align": all_a_res,
                  "lang": all_l_res,
                  "vision": vis_logits,
              }
          else:
              logits = align_logits
      if self.training:
          return logits
      else:
          return F.softmax(logits, -1)
  
imports: import math
  import paddle
  from paddle import nn
  import paddle.nn.functional
  from paddle.nn import LayerList
  from ppocr.modeling.heads.rec_nrtr_head import TransformerBlock, PositionalEncoding
label_desc: Use image node_id 2 for calling the ABINetHead obj's underlying member method code with example usage: obj.forward(x, targets) and returns: logits, F, dict