Imprimir las permutaciones únicas de un arreglo con algunos elementos repetidos

echo '<pre>';
print_r(permutations([1, 2, 3, 4], 0));
echo '</pre>';

output:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
            [3] => 4
        )

    [1] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 4
            [3] => 3
        )

    [2] => Array
        (
            [0] => 1
            [1] => 3
            [2] => 2
            [3] => 4
        )

    [3] => Array
        (
            [0] => 1
            [1] => 3
            [2] => 4
            [3] => 2
        )

    [4] => Array
        (
            [0] => 1
            [1] => 4
            [2] => 3
            [3] => 2
        )

    [