code: def change_activation_to_prelu(self):
      for op in self._model.op:
          if (
              op.type == ApuOp.Activation.name
              and ConverterUtil.get_arg(
                  op, MaceKeyword.mace_activation_type_str
              ).s
              == b"PRELU"
          ):
              op.type = ApuOp.PRelu.name
  
imports: import copy
  import numpy
  from enum import Enum
  from operator import mul
  from py_proto import mace_pb2
  from transform import base_converter
  from transform.base_converter import ConverterUtil
  from transform.base_converter import EltwiseType
  from transform.base_converter import MaceKeyword
  from transform.base_converter import MaceOp
  from transform.base_converter import PaddingMode
  from transform.base_converter import PadType
  from transform.base_converter import PoolingType
  from transform.base_converter import ReduceType
  from transform.base_converter import DataFormat
  from transform.base_converter import FrameworkType
  from utils.util import mace_check
label_desc: Use image node_id 16 for calling the ApuConverter obj's underlying member method code with example usage: obj.change_activation_to_prelu() without return types