The Symbol.toStringTag static data property represents the well-known symbol Symbol.toStringTag. Object.prototype.toString() looks up this symbol on the this value for the property containing a string that represents the type of the object.

The Promise.withResolvers() static method returns an object containing a new Promise object and two functions to resolve or reject it, corresponding to the two parameters passed to the executor of the Promise() constructor.

The Promise.try() static method takes a callback of any kind (returns or throws, synchronously or asynchronously) and wraps its result in a Promise.

The prototype property of AsyncGeneratorFunction.prototype is shared by all async generator functions. Its value is AsyncGenerator.prototype. Each async generator function created with the async function* syntax or the AsyncGeneratorFunction() constructor also has its own prototype property, whose prototype is AsyncGeneratorFunction.prototype.prototype. When the async generator function is called, its prototype property becomes the prototype of the returned async generator object.

The ReferenceError() constructor creates ReferenceError objects.

The AsyncGeneratorFunction() constructor creates AsyncGeneratorFunction objects.

The Object.groupBy() static method groups the elements of a given iterable according to the string values returned by a provided callback function. The returned object has separate properties for each group, containing arrays with the elements in the group.

The lastIndexOf() method of Array instances returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

The find() method of Array instances returns the first element in the provided array that satisfies the provided testing function. If no values satisfy the testing function, undefined is returned.

The then() method of Promise instances takes up to two arguments: callback functions for the fulfilled and rejected cases of the Promise. It stores the callbacks within the promise it is called on and immediately returns another Promise object, allowing you to chain calls to other promise methods.