Exercise $2.$ Fibonacci sequence $(55$pts$).$

The famous Fibonacci Sequence is the series of numbers like this: $0,1,1,2,3,5,8,13,21,34,...$ The next number is found by adding up the two numbers prior to it$.-2$ is found by adding the two numbers before it $(1+1)-3$ is found by adding the two numbers before it $(1+2),-5$ is $(2+3),-......$

An implementation could be like this:

def fibonacci$($num$)$:

if num $<2$:

return num

return fibonacci$($num $-1)+$ fibonacci$($num $-2)$

But the runtime performance is terrible. This is because the code keeps recalculating Fibonacci numbers that are already known. $1.$

Implement a @cache decorator that will save the calculations in a function attribute dictionary. Even though the function fibonacci$($num$)$ only has one input argument, please make the decorator work for functions with any number of arguments $($the decorator$$s own arguments can be ignored$).$