code: def get_only_parent(self):
      if len(self.parents) != 1:
          raise ConversionError(
              "Node (%s) expected to have 1 parent. Found %s."
              % (self, len(self.parents))
          )
      return self.parents[0]
  
imports: from collections import namedtuple
  from functools import reduce
  from google.protobuf import text_format
  from copy import deepcopy
  import numbers
  import os
  import tempfile
  from mmdnn.conversion.caffe.mapper import get_handler_name
  from mmdnn.conversion.caffe.resolver import get_caffe_resolver, has_pycaffe
  from mmdnn.conversion.caffe.shape import *
  from mmdnn.conversion.caffe.errors import print_stderr, ConversionError
label_desc: Use image node_id 3 for calling the CaffeNode obj's underlying member method code with example usage: obj.get_only_parent() and returns: self