Write a function to swap two numbers.
def swap_numbers(a,b):
 temp = a
 a = b
 b = temp
 return (a,b)
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to swap two numbers.
def swap_numbers(a,b):
 temp = a
 a = b
 b = temp
 return (a,b)[/INST]assert swap_numbers(10,20)==(20,10)
assert swap_numbers(15,17)==(17,15)
assert swap_numbers(100,200)==(200,100)</s>