import { CommandRegistry } from '@phosphor/commands'; const registry = new CommandRegistry(); const printHelloCommand = { label: 'Say Hello', execute: () => console.log('Hello!') }; registry.addCommand('print-hello', printHelloCommand);In this example, we create a new `CommandRegistry`, and then define a command object called `printHelloCommand` that has a label of "Say Hello" and a callback function that logs "Hello!" to the console. We then add this command to the registry using the `addCommand` method, with the unique identifier "print-hello". Overall, `@phosphor/commands` is a powerful TypeScript package that provides a robust framework for handling user commands in a web application. Its `CommandRegistry` class and `addCommand` method make it easy to define and execute custom commands, enabling developers to create rich and intuitive user interfaces.