如何防止SerializeJSON将Yes/No/True/False字符串更改为boolean？

var data = {
  options: ["Yes", "No", "True", "False"]
};

function customSerialize(obj) {
  return JSON.stringify(obj, function(key, value) {
    if (value === 'Yes' || value === 'No' || value === 'True' || value === 'False') {
      return value.toString();
    }
    return value;
  });
}

var data = {
  option1: 'Yes',
  option2: 'No',
  option3: 'True',
  option4: 'False'
};

var jsonString = customSerialize(data);

var stringifySafe = require('json-stringify-safe');

var data = {
  option1: 'Yes',
  option2: 'No',
  option3: 'True',
  option4: 'False'
};

var jsonString = stringifySafe(data, function(key, value) {
  if (value === 'Yes' || value === 'No' || value === 'True' || value === 'False') {
    return value.toString();
  }
  return value;
});