Create a function that takes an empty function as a string and returns the function as a arrow function.
"function test(a) {}" ➞ "const test = (a) =>"
"function twoArgs(a,b) {}" ➞ "const twoArgs = (a,b) =>"
"function restArgs(...a) {}" ➞ "const restArgs = (...a) =>"
const.