Duplicate fixtures in tests

There are many duplicate user agents in /Tests/fixtures/ folder. Here are just a few examples :

Mozilla/5.0 (Linux; Android 5.1; HiBox-hero) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.62 Safari/537.36

Mozilla/5.0 (Linux; Android 9; HLTE720T Build/PKQ1.190302.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/76.0.3809.89 Mobile Safari/537.36

Mozilla/5.0 (Linux; U; Android 4.4.4; en-US; SM-G5306W Build/KTU84P) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/57.0.2987.108 UCBrowser/12.10.3.1199 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 5.0.2; SM-S920L) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.92 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 5.1.1; SM-G530R7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.99 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 5.1.1; SAMSUNG-SM-G530A) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.93 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 5.1.1; SM-N920X Build/LMY47X) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.158 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N920R7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N930S) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.136 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N930T) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.162 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N9300) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N930V) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.83 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 6.0.1; SM-N930P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 YaBrowser/19.3.3.285.00 Mobile Safari/537.36

Mozilla/5.0 (Linux; Android 5.1.1; Xperia Z Ultra) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.96 Mobile Safari/537.36

Microsoft-Windows-XP/2002, UPnP/1.1, J. River Internet Reader/2.0 (compatible; Windows-Media-Player/10)

RadioPublic/android-2.2

GooglePodcasts/2.0.2 iPod_touch/13.4.1 hw/iPod9_1

Spotify/120800923 OSX/0 (MacBookPro6,2)

AmazonMusic

KaiOS Downloader PodKast

Procast (iOS)

...

Maybe it would be valuable to write a test to check duplicate fixtures

Start by inspecting the user-agent fixtures in /Tests/fixtures/ and identify how duplicate entries are represented. Review the existing tests to determine where a duplicate-fixture check belongs. Done means redundant fixtures are removed and, if appropriate, a test prevents duplicates from being added again.