cannot be applied to given types;
[ERROR] required: int[]
[ERROR] found: int,int,int,int
reason: actual and formal argument lists differ in length

@Test
public void whenTurnArrayWithEvenAmountOfElementsThenTurnedArray() {
    Turn turn = new Turn();
    int[] resultArray = turn.back(4, 1, 6, 2);
    int[] expectArray = turn.back(2, 6, 1, 4);
    assertThat(resultArray, is(expectArray));
}

public int[] back(int[] array) {
    for (int i = 0; i < array.length / 2; i++) {
            int k = array[i];
            array[i] = array[array.length - i + 1];
            array[array.length - i + 1] = k;
        }
    return array;
    }

@Test
public void whenTurnArrayWithEvenAmountOfElementsThenTurnedArray() {
    Turn turn = new Turn();
    int[] resultArray = turn.back(new int[] {4, 1, 6, 2});
    int[] expectArray = new int[] {2, 6, 1, 4};
    assertThat(resultArray, is(expectArray));
}

public int[] back(int... array) {
    for (int i = 0; i < array.length / 2; i++) {
        int k = array[i];
        array[i] = array[array.length - i + 1];
        array[array.length - i + 1] = k;
    }
    return array;
}

@Test
public void whenTurnArrayWithEvenAmountOfElementsThenTurnedArray() {
    Turn turn = new Turn();
    int[] resultArray = turn.back(4, 1, 6, 2);
    int[] expectArray = new int[] {2, 6, 1, 4};
    assertThat(resultArray, is(expectArray));
}