If a devisee who is a grandparent or a lineal descendant of a grandparent of the testator is dead at the time of execution of the will, fails to survive the testator, or is treated as if the devisee predeceased the testator, the issue of the deceased devisee who survive the testator by one hundred twenty hours take in place of the deceased devisee and if they are all of the same degree of kinship to the devisee they take equally, but if of unequal degree, then those of more remote degree take by representation. One who would have been a devisee under a class gift if that person had survived the testator is treated as a devisee for purposes of this section where that person’s death occurred before or after the execution of the will.