Data Structures: Use .has and .size on an ES6 Set

Anyone help me see what I am doing wrong with this part? Here is the page for the challenge.

function checkSet(arrToBeSet, checkValue){

   // change code below this line
   var set = new Set([ 4, 5, 6]);
   var hasThree = set.has(3);
   var howBig = set.size;
   // change code above this line

}

checkSet([ 1, 2, 3], 2); // Should return [ true, 3 ]

The challenge asks you to create a function that check if a given array has a specific value and what is the length of the array. Try to think. The challenge gives you some clues. Try to use the parameter instead of using numbers here: