[COMPLETE USE CASE TEST FLOW SETUP] - ORIGINATOR

[raymond-jgler]

This is the parent ticket containing all related details regarding functional testing,
children tickets are :
_ folder structure changes : #22
_ phase pattern : #24, #25 , #26 , #27
_ combined logic test: #28

Because our test case is an existing Java file,
and the functional logic is comprised of phases to finally modify the Java file.

Our phase logic contains :
_ VALIDATE CLASS PHASE
_ VALIDATE FIELD PHASE
_ BUILD CODE PHASE
_ WRITE NEWLY-MODIFIED CODE PHASE

The current phase's input is the previous output of its previous one,
this bears a resemblance to Chain Of Responsibility design pattern:
it will exit if any phase's output is unqualified.