And: When a method terminates, its memory is forgotten from the stack and the pointer is readjusted.
Next: This program contains eight important methods: A1 through D1, and A2 through D2.
Info: When A1 is called, it calls B1 and then B1 calls C1. On the other hand, when A2 is called, it simply calls B2, C2, and D2.
Important: The A2 method should consume less stack space. It has a shorter stack.
Also: The Exception throws in the program are to confuse the inliner in the JIT.
However: This is likely not useful except on performance-critical parts of important programs.