/**
 * A class representing a HelloWorld greeter with various utility methods
 * @class HelloWorld
 */
class HelloWorld {
    // Version number of the HelloWorld class
    static VERSION = '1.0.0';
    // Counter to track number of class instances
    static #instanceCount = 0;

    // Private instance fields
    #name;
    #options;
    #createdAt;

    /**
     * Creates a new HelloWorld instance
     * @param {string} name - The name to use for greetings
     * @param {Object} options - Configuration options
     */
    constructor(name = 'World', options = {}) {
        this.#name = name;
        this.#options = options;
        this.#createdAt = new Date();
        HelloWorld.#instanceCount++;
    }

    static getInstanceCount() {
        return HelloWorld.#instanceCount;
    }

    get name() {
        return this.#name;
    }

    set name(value) {
        this.#name = value;
    }

    async greet(...names) {
        try {
            for (const name of names) {
                await new Promise(resolve => setTimeout(resolve, 100));
                console.log(`Hello, ${name}!`);
            }
        } catch (error) {
            console.error(`Error: ${error.message}`);
        }
    }

    configure(options = {}) {
        Object.assign(this.#options, options);
    }

    *generateSequence(start = 0, end = 10) {
        for (let i = start; i <= end; i++) yield i;
    }

    processNames(names) {
        return names
            .filter(name => name.length > 0)
            .map(name => name.toUpperCase())
            .sort();
    }
}

const greeter = new HelloWorld('JavaScript');

(async () => {
    const uniqueNames = new Set(['Alice', 'Bob']);
    await greeter.greet(...uniqueNames);

    for (const num of greeter.generateSequence(0, 5)) {
        console.log(num);
    }
})();