Define a function big_and_small that consumes a value and returns a tuple of two numbers: twice the value and half the value. Then, you will need to call your function once to create two variables "twice" and "half" for the number 30.
Note: Your function will be unit tested against multiple arguments. It is not enough to get the right output for your own test cases; you will need to be able to handle any kind of number.
Note: You are not allowed to use list or tuple indexing (but you can use multiple assignment).
Note: You may only call your function once.