NewTester creates a new Tester func NewTester(httpClient *http.Client, host, rtmpHost, mediaHost string, port, rtmpPort, mediaPort uint, checkInterval time.Duration, minSuccessRate float64, numStreamsInit, numStreamsStep uint, alert func(string, *Result)) *Tester {.

Result contains the results of the Run() function.

Tester maintains each individual test run.