Despite there being a section in RFC 7231 <https://tools.ietf.org/html/rfc7231#section-5.5.3> defining a suggested structure for 'User-Agent' headers this data is notoriously difficult to parse consistently. Tools are provided that will take in user agent strings and return structured R objects. This is a 'V8'-backed package based on the 'ua-parser' project <https://github.com/ua-parser>.