Although the class TestFrame1 has been defined it is not instantiated.
The main() method is a static part of that class, not
part of any object.
Review the beginning chapter on objects (currently chapter 25)
if this is unclear.
Here is a picture of what is going on:
Although the main() method is static,
it can ask to create an object (with new) and
its variable frame can refer to that object
in main memory.