code: def optimizer(self, value):
      assert self._optimizer is None, "optimizer has already been set"
      self._optimizer = value
  
file_path: pytorch/caffe2/python/modeling/parameter_info.py
imports: from caffe2.python import core
  import numpy
label_desc: Use image node_id 4 for calling the ParameterInfo obj's underlying member method code with example usage: obj.optimizer(value) without return types