code: function assertArguments(options, argnames) {
    if (!argnames) return;
    if (!options) throw new TypeError('missing arguments: ' + argnames);
    argnames.forEach(function (argname) {
      if (!options.hasOwnProperty(argname)) {
        throw new TypeError('missing argument: ' + argname);
      }
    });
  }
docs: Convenience method to assert that a given options object contains the required arguments.
  
  @param options
  @param argnames