class Selenium::WebDriver::Remote::Driver

def generate_capabilities(capabilities)
  Array(capabilities).map { |cap|
    if cap.is_a? Symbol
      cap = WebDriver::Options.send(cap)
    elsif !cap.respond_to? :as_json
      msg = ":capabilities parameter only accepts objects responding to #as_json which #{cap.class} does not"
      raise ArgumentError, msg
    end
    cap.as_json
  }.inject(:merge)
end