def post(path, payload, additional_options = {})
      raise PayloadError.new, Nokogiri::XML(payload).errors if Nokogiri::XML(payload).errors.any?
      request 'POST', path, { body: payload }.merge(additional_options)
    end
def post(path, payload, additional_options = {})
      raise PayloadError.new, Nokogiri::XML(payload).errors if Nokogiri::XML(payload).errors.any?
      request 'POST', path, { body: payload }.merge(additional_options)
    end
additional_options: { query: { foo: 'bar' } }