docs: function initServer (args) {
      // get server args
      var server = requireValidOptionalObject(args.server)
      // create module methods
      moduleMethods.forEach(methodName => {
          var method = server[methodName]
          // skip if no method in args
          if (!defined(method)) {
              return
          }
          // require function
          this.assert(typeof method === 'function', 110, `${methodName} method must be function`)
          // create module method
          this.module.method(methodName, method)
      })
  }