code: def _format(self, title, key_values):
      if len(key_values) == 0:
          return ""
      tbl = _PrettyTable(header=False)
      for k, v in six.iteritems(key_values):
          tbl.add_row([k, v])
      tbl.align["Field 1"] = "l"
      tbl.align["Field 2"] = "l"
      s = title + ":\n"
      s += tbl.__str__() + "\n"
      return s
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import turicreate
  from turicreate.toolkits._model import CustomModel
  from prettytable import PrettyTable
  from turicreate.toolkits._internal_utils import _precomputed_field, _toolkit_repr_print
  import six
label_desc: Use image node_id 4 for calling the GraphAnalyticsModel obj's underlying member method code with example usage: obj._format(title, key_values) and returns: s, str