code: def _init_layers(self):
      self.ref_point_head = build_MLP(
          self.embed_dims * 2, self.embed_dims, self.embed_dims, 2
      )
      self.norm = nn.LayerNorm(self.embed_dims)
  
imports: import math
  import warnings
  import torch
  import torch.nn
  from mmcv.cnn import build_norm_layer
  from mmcv.cnn.bricks.transformer import BaseTransformerLayer, TransformerLayerSequence, build_transformer_layer_sequence
  from mmcv.ops import MultiScaleDeformableAttention
  from mmengine.model import BaseModule
  from mmengine.model.weight_init import xavier_init
  from torch.nn.init import normal_
  from mmdet.models.layers.transformer import inverse_sigmoid
  from mmdet.registry import MODELS
label_desc: Use image node_id 2 for calling the DinoTransformerDecoder obj's underlying member method code with example usage: obj._init_layers() without return types