class_docstr: The ViT-Adapter
      
code: def forward(self, x):
      deform_inputs1, deform_inputs2 = deform_inputs(x)
  
      # SPM forward
      c1, c2, c3, c4 = self.spm(x)
      c2, c3, c4 = self._add_level_embed(c2, c3, c4)
      c = paddle.concat([c2, c3, c4], axis=1)
  
      # Patch Embedding forward
      x, H, W = self.patch_embed(x)
      bs, n, dim = x.shape
      pos_embed = self._get_pos_embed(self.pos_embed[:, 1:], H, W)
      x = self.pos_drop(x + pos_embed)
  
      # Interaction
      outs = list()
      for i, layer in enumerate(self.interactions):
          indexes = self.interaction_indexes[i]
          x, c = layer(
              x,
              c,
              self.blocks[indexes[0] : indexes[-1] + 1],
              deform_inputs1,
              deform_inputs2,
              H,
              W,
          )
          outs.append(x.transpose([0, 2, 1]).reshape([bs, dim, H, W]))
  
      # Split & Reshape
      c2 = c[:, 0 : c2.shape[1], :]
      c3 = c[:, c2.shape[1] : c2.shape[1] + c3.shape[1], :]
      c4 = c[:, c2.shape[1] + c3.shape[1] :, :]
  
      c2 = c2.transpose([0, 2, 1]).reshape([bs, dim, H * 2, W * 2])
      c3 = c3.transpose([0, 2, 1]).reshape([bs, dim, H, W])
      c4 = c4.transpose([0, 2, 1]).reshape([bs, dim, H // 2, W // 2])
      c1 = self.up(c2) + c1
  
      if self.add_vit_feature:
          x1, x2, x3, x4 = outs
          x1 = F.interpolate(
              x1, scale_factor=4, mode="bilinear", align_corners=False
          )
          x2 = F.interpolate(
              x2, scale_factor=2, mode="bilinear", align_corners=False
          )
          x4 = F.interpolate(
              x4, scale_factor=0.5, mode="bilinear", align_corners=False
          )
          c1, c2, c3, c4 = c1 + x1, c2 + x2, c3 + x3, c4 + x4
  
      # Final Norm
      f1 = self.norm1(c1)
      f2 = self.norm2(c2)
      f3 = self.norm3(c3)
      f4 = self.norm4(c4)
      return [f1, f2, f3, f4]
  
imports: import math
  from functools import partial
  import numpy
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import manager
  from paddleseg.utils import utils, logger
  from paddleseg.cvlibs.param_init import normal_init, trunc_normal_init, constant_init
  from paddleseg.models.backbones.transformer_utils import to_2tuple, DropPath
  from paddleseg.models.layers.vit_adapter_layers import SpatialPriorModule, InteractionBlock, deform_inputs
  from paddleseg.models.layers.ms_deformable_attention import MSDeformAttn
label_desc: Use image node_id 6 for calling the ViTAdapter obj's underlying member method code with example usage: obj.forward(x) and returns: list