Fix unit functions that are not invoked

Fix unit functions that are not invoked

- Issue:
Some internal functions are not invoked from business logic.

- Solution:
Some functions are predefined for future needs, but they are note called
yet. So, these functions decrease the line coverage. To solve this issue,
this patch removes those dead functions.
And also, this patch invokes a dead function. This function has purpose
and code that needs to invoke this function, but current code does not
use it. Through this patch, this function is invoked and covered by test
case.

Change-Id: I33b882525e99ca251644aedbe7b18cf938dc17ff
Signed-off-by: Suyeon Hwang <stom.hwang@samsung.com>