code: function validate (host) {
    const hostScheme = joi.array()
      .items(joi.string().min(1))
      .min(1).single()
  
    joi.assert(host, hostScheme, 'The parameter `host` is invalid. Its')
  }
docs: @function
  @private
  
  Validate the plugin's options
  
  @param {string} host The host to filter by virtual host
  @throws The options are invalid