Android Developer This Class Is Not Available With API Level 15

When searching on you might run into this message you can’t close or so it seems. The error message:

This class is not available with API level 15.
To use this class, you must develop your app using a build target that supports API level 16 or higher. To read these APIs, change the value of the API level filter above.
What is the API level?

When scrolling the message doesn’t disappear. As the message says the class can’t run with API level 15. So to change the API level look at the top left. You’ll see “API Level: XX”.

Change this to 16 and the message will disappear.