code: def reset_classifier(self, num_classes, global_pool=""):
      self.num_classes = num_classes
      self.head = (
          nn.Linear(self.embed_dim, num_classes)
          if num_classes > 0
          else nn.Identity()
      )
  
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 7 for calling the MixVisionTransformer obj's underlying member method code with example usage: obj.reset_classifier(num_classes, global_pool) without return types