def process
      status, headers, body = Jets.application.call(env)
      convert_to_api_gateway(status, headers, body)
    end
def process
      status, headers, body = Jets.application.call(env)
      convert_to_api_gateway(status, headers, body)
    end
1. Convert API Gateway event event to Rack env
 2. Process using full Rack middleware stack
 3. Convert back to API gateway response structure payload