code: function isValidJSON(arg) {
      var parsed;
      if (!lodash.isString(arg)) {
        return false;
      }
      try {
        parsed = JSON.parse(arg);
      } catch (e) {
        return false;
      }
      if (typeof(parsed) === 'object') {
        return true;
      }
      return false;
    }
docs: Test if an argument is a valid JSON object. If it is, returns a truthy
  value (the json object decoded), so no double JSON.parse call is necessary
  
  @param {string} arg
  @return {Object|boolean} false if the argument is not a JSON string.