Translate CSS Selectors to XPath Expressions
c(person("Simon", "Potter",
                    role = c("aut", "trl", "cre"),
                    email = "simon@sjp.co.nz"),
             person("Simon", "Sapin", role = "aut"),
             person("Ian", "Bicking", role = "aut"))
Translates a CSS3 selector into an equivalent XPath
  expression. This allows us to use CSS selectors when working with
  the XML package as it can only evaluate XPath expressions. Also
  provided are convenience functions useful for using CSS selectors on
  XML nodes. This package is a port of the Python package 'cssselect'
  (<https://cssselect.readthedocs.io/>).
Simon Potter [aut, trl, cre],
  Simon Sapin [aut],
  Ian Bicking [aut]