I have discovered that the following test user agent is recognized as a bot:

Google-HTTP-Java-Client/1.17.0-rc (gzip)
/Tests/Parser/Client/fixtures/library.yml, line 105

This is due to the following regular expression:

Googlebot(-Mobile|-Image|-Video|-News)?|Feedfetcher-Google|Google Web Preview|AdsBot-Google(-Mobile)?|APIs-Google|Mediapartners-Google|Google.*/\+/web/snippet|GoogleProducer|Google[ -]Publisher[ -]Plugin|Google-(AMPHTML|Test|Site-Verification|Shopping-Quality|Adwords-DisplayAds|Assess|AdWords-Express|Adwords-Instant|speakr|Read-Aloud|Youtube-Links|HotelAdsVerifier)?
/regexes/bots.yml, line 628

Especially the last part of the query: (...|Google-(...)?)

But if I understand it correctly, it is a public Java library provided by Google.

Thank you for your great job.
André Kornetzky