Provide me with explanation for given snippet, ensure the explaination is clear, concise and readable.
The provided code is an implementation of a Lighthouse audit called "AsyncAdTags" that checks whether ad tags are loaded asynchronously on a web page. Here's a breakdown of the key components:
Imports and Dependencies: The code imports necessary modules and utilities to perform the audit, including network-related modules and i18n for internationalization support.
UIStrings: This object contains the UI text and titles used in the audit, providing translations and messaging for the results of the audit.
isAsync Function: function determines whether a given network request for an ad tag is asynchronous by checking its priority and classifying it as asynchronous if it meets specific criteria.
AsyncAdTags Class: This class extends the Audit class and defines the audit logic. It includes a static meta method that provides metadata for the audit, such as its ID, title, description, and required artifacts. The audit method performs the actual audit by analyzing network records and main resources to check if ad tags are loaded asynchronously. If no ad tags are found, the audit returns a "not applicable" result. Otherwise, it calculates the number of synchronous ad tag requests and determines whether the page passes the audit based on this count.
Export: The class AsyncAdTags is exported as the default export of the module, allowing it to be used as a standalone audit. Additionally, the UIStrings object is also exported, though its usage is not explicitly shown in the code snippet.
Overall, this code snippet provides a structured and modular implementation of an audit that checks the asynchronous loading of ad tags on web pages, contributing to the overall performance and user experience of the site.