code: def convert(self, value, param, ctx):
      if not isinstance(value, strtype):
          # Already a correct type
          return value
      try:
          return json.loads(value)
      except:
          self.fail("%s is not a valid JSON object" % value, param, ctx)
  
imports: import json
  from typing import Any, Callable, Dict, NamedTuple, Optional, Type, Union
  from metaflow._vendor import click
  from .util import get_username, is_stringish
  from .exception import ParameterFieldFailed, ParameterFieldTypeMismatch, MetaflowException
label_desc: Use image node_id 1 for calling the JSONTypeClass obj's underlying member method code with example usage: obj.convert(value, param, ctx) and returns: value, json