[UNIT TEST]Add couple of unit tests for the funtion encrypt_pdf()

[nirmalchandra]

AC1:

Add unit tests to cover this function:

def encrypt_pdf(input_pdf, output_pdf, password):

[HuyCaoWorkspace]

hi @nirmalchandra , I would like to work on this issue, can you assign this to me?

[nirmalchandra]

hi @nirmalchandra , I would like to work on this issue, can you assign this to me?

Hey @HuyCaoWorkspace , done. Please proceed.
And thanks for picking this 👋

[HuyCaoWorkspace]

hey @nirmalchandra , sorry to inform you this, due to personal reasons I cannot work on this issue anymore, please accept my apology and assign this issue to other people.