75         const callback = tock.callback;
77           callback();
81             case 1: callback(args[0]); break;
82             case 2: callback(args[0], args[1]); break;
83             case 3: callback(args[0], args[1], args[2]); break;
84             case 4: callback(args[0], args[1], args[2], args[3]); break;
85             default: callback(...args);
103 function nextTick(callback) {  argument
104   validateFunction(callback, 'callback');
128     callback,  property
138     const callback = this.callback;
140       callback();
149 function queueMicrotask(callback) {  argument
150   validateFunction(callback, 'callback');
156   asyncResource.callback = callback;