docs: function defaultFormatter (name, options) {
    // Return string will be passed to logger.
    let message = (options.message ? options.message : '')
    const now = new Date().toISOString()
  
    // if meta is an error, print error stack, else pretty print meta as JSON
    if (options.meta) {
      if (options.meta.stack) {
        const stack = options.meta.stack
        message += `\n${stack.join ? stack.join('\n') : stack}`
      } else if (Object.keys(options.meta).length) {
        message += `\n${JSON.stringify(options.meta, null, 2)}`
      }
    }
  
    return `${options.level.toUpperCase()} ${now} ${name} ${message}`
  }