Web Crawler with Multithreading

Build a multithreaded web crawler to retrieve up to 100 distinct URLs. The initial URL will be provided as a command line argument. The crawler should visit sites concurrently and stop when either 100 URLs have been retrieved or no further links can be followed. Requirements: Use multithreading to improve crawling efficiency. Each thread should handle a different URL. The data structure should prevent duplicate URL visits. Output each visited URL to the console. Test cases: Input: https://example.com Input: https://xyz.io Input: https://mytest.org Example Input https://example.com