class_docstr: JSON format parser for protocol message.
docstr: Convert map field value for a message map field.
  
  Args:
    value: A JSON object to convert the map field value.
    message: A protocol message to record the converted data.
    field: The descriptor of the map field to be converted.
  
  Raises:
    ParseError: In case of convert problems.
docstr_tok: ["Convert","map","field","value","for","a","message","map","field",".","Args",":","value",":","A","JSON","object","to","convert","the","map","field","value",".","message",":","A","protocol","message","to","record","the","converted","data",".","field",":","The","descriptor","of","the","map","field","to","be","converted",".","Raises",":","ParseError",":","In","case","of","convert","problems","."]
code: def _ConvertMapFieldValue(self, value, message, field):
      """Convert map field value for a message map field.
  
      Args:
        value: A JSON object to convert the map field value.
        message: A protocol message to record the converted data.
        field: The descriptor of the map field to be converted.
  
      Raises:
        ParseError: In case of convert problems.
      """
      if not isinstance(value, dict):
          raise ParseError(
              "Map field {0} must be in a dict which is {1}.".format(
                  field.name, value
              )
          )
      key_field = field.message_type.fields_by_name["key"]
      value_field = field.message_type.fields_by_name["value"]
      for key in value:
          key_value = _ConvertScalarFieldValue(key, key_field, True)
          if (
              value_field.cpp_type
              == descriptor.FieldDescriptor.CPPTYPE_MESSAGE
          ):
              self.ConvertMessage(
                  value[key], getattr(message, field.name)[key_value]
              )
          else:
              getattr(message, field.name)[
                  key_value
              ] = _ConvertScalarFieldValue(value[key], value_field)
  
imports: import base64
  from collections import OrderedDict
  import json
  import math
  from operator import methodcaller
  import re
  import sys
  from google.protobuf.internal import type_checkers
  from google.protobuf import descriptor
  from google.protobuf import symbol_database
label_desc: Use image node_id 10 for calling the _Parser obj's underlying member method code with example usage: obj._ConvertMapFieldValue(value, message, field) without return types