docs: function encryptLogField(logData, fieldName) {
      if (typeof logData[fieldName] === 'undefined' || !logData[fieldName]) return;
      if (typeof logData[fieldName] === 'object') {
        try {
          logData[fieldName] = JSON.stringify(logData[fieldName]);
        } catch (e) {
          console.warn('loglet: Could not stringify field ' + fieldName + ' of a log entity.');
          return;
        }
      } else if (typeof logData[fieldName] !== 'string') {
        logData[fieldName] = logData[fieldName].toString();
      }
      var enc = util.encrypt(logData[fieldName], secret, true);
      if (!enc) {
        console.warn('loglet: Could not encrypt field ' + fieldName + ' of a log entity.');
        return;
      }
      logData[fieldName] = enc;
    }