@joshi.rohit100 Thanks for the review. I am not sure about your first suggest...

@joshi.rohit100 Thanks for the review. I am not sure about your first suggestion. There's an issue for this #1942432: Use extension_loaded instead of function_exists to detect PHP extensions, the comment [#1942432.4] is quite interesting and is the reason why I don't want to use extension_loaded(). Also I took the code from simpletest_requirements(), I am inclined towards function_exists(). Can you please test this patch.