class Selenium::WebDriver::Remote::Response

def add_backtrace(ex)
  return unless value.is_a?(Hash) && value['stackTrace']
  server_trace = value['stackTrace']
  backtrace = server_trace.map do |frame|
    next unless frame.is_a?(Hash)
    file = frame['fileName']
    line = frame['lineNumber']
    meth = frame['methodName']
    class_name = frame['className']
    file = "#{class_name}(#{file})" if class_name
    meth = 'unknown' if meth.nil? || meth.empty?
    "[remote server] #{file}:#{line}:in `#{meth}'"
  end.compact
  ex.set_backtrace(backtrace + ex.backtrace)
end