xxxxxxxxxx
-------------- ------------
| User | | Course |
-------------- ------------
| -name | | -title |
| -email | | -description |
| -password | | -content |
|--------------| |------------|
| +subscribe() | | +upload() |
| +gift() | | +manage() |
| +viewDetails()| |------------|
-------------- | | | |
| -----------
| | Subscription|
| | Gift |
------------------- -------------