We require a simple function to verify that a given URL is a valid image and also that it checks for a valid image size.
A regular expression check is useless as it cannot verify that it is an actual image.
HEAD method check should be done.
Also, it should check for sizes and not exceed 600x400 px.
TRUE: valid image and valid size.
FALSE: not valid image or not valid size.
ATTENTION: Function MUST be provided in less than 10 hours of project winning.