how to use https for mydomain.appspot.com

[Sarvesh Kushwaha]

i want to ask what shoul i ad in app.yaml to use https by-default for my appspot domain , which is like mydomain.appspot.com . and 

i want to redirect evry http , www , https request to single domain like https://www.mydomain.appsopt.com . please help me out .

i used .htacess file to redirect to single domain but its not working in appspot .