Write a method, that returns the first index of the first location in the partially filled array that contains the specified key, or -1 if the key is not in the partially filled array. size will always be at least 0 and at most the length of the array. NOTE: In a "partially filled" array, the variable size indicates how many of the elements in that array (beginning at index 0) actually are "in use". For example, given the array {4, 7, 2, 5, 1, 4, 8} and a size of 3 then only the first 3 elements in that array (4, 7, and 2) are actually considered "in use".