Write a function to calculate the value of 'a' to the power 'b'.
def power(a,b):
	if b==0:
		return 1
	elif a==0:
		return 0
	elif b==1:
		return a
	else:
		return a*power(a,b-1)
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to calculate the value of 'a' to the power 'b'.
def power(a,b):
	if b==0:
		return 1
	elif a==0:
		return 0
	elif b==1:
		return a
	else:
		return a*power(a,b-1)[/INST]assert power(3,4) == 81
assert power(2,3) == 8
assert power(5,5) == 3125</s>