This is a function to save every executed line of code as
history when the program is executed. The execution history
is expected to include every associated line number to save
as well; duplicate lines can also be included. Every duplicate
line is counted to determine how many lines were executed.
The execution history thus obtained is expected to
include every unique feature of the functionalities executed.
Thereby two execution histories are created, each of which
corresponds to every different functionality that is executed.
Taking the differences from the two histories, we will be
able to find and extract the unique segments of the program.