code: function (lines, ip, host) {
      // Try to remove entry, if it exists
      lines = lines.filter(function (line) {
        return !(Array.isArray(line) && line[0] === ip && line[1] === host);
      });
      return lines;
    }
docs: Remove a rule from /etc/hosts. If the rule does not exist, then this does
  nothing.
  
  @param  {string}   ip
  @param  {string}   host
  @param  {function(Error)} cb