code: def init_weight(self):
      if self.pretrained is not None:
          utils.load_pretrained_model(self, self.pretrained)
      else:
          self.apply(self._init_weights)
  
imports: import math
  from functools import partial
  import paddle
  import paddle.nn
  import paddle.nn.functional
  import paddle.nn.initializer
  from paddleseg.cvlibs import manager
  from paddleseg.utils import utils
  from paddleseg.models.backbones.transformer_utils import *
label_desc: Use image node_id 2 for calling the MixVisionTransformer obj's underlying member method code with example usage: obj.init_weight() without return types